Contact resistance tester for switch equipment contact

Abstract

The utility model discloses a contact resistance tester for a switch equipment contact, and belongs to the technical field of power equipment detection. According to the utility model, the super capacitor module, the voltage sampling and scaling module, the current sampling module, the super capacitor charging module, the pulse current control module and the data processing module are electrically connected; the super-capacitor module is charged through the super-capacitor charging module, so that the super-capacitor module can charge the super-capacitor, the super-capacitor is controlled through the pulse current control module, pulse current is generated, stable large pulse current can be applied to a contact resistor of a contact, and the contact resistor of the contact is protected. The voltage sampling and scaling module and the current sampling module are used for sampling the voltage and the current of the contact resistance of the contact, and then the data processing module is used for detecting the contact resistance of the contact; the problem of inaccurate measurement of the contact resistance of the contact in the prior art can be solved, and the accuracy of measurement of the contact resistance of the contact is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of power equipment detection, especially relates to a switch device contact contact resistance tester. BACKGROUND

[0002] As an important part of the power system, the high-voltage switch device is a key device for controlling, protecting, isolating and distributing electric energy in the power system, and is widely used in power generation, power transmission, power transformation and power distribution. The contact electric contact state of the high-voltage switch device is crucial to the reliability and safety of the device operation. Abnormal increase of the contact contact resistance may cause local overheating, welding and even failure of the high-voltage switch device, which will affect the stable operation of the power system. Therefore, monitoring the contact contact resistance is crucial to maintaining the stable operation of the high-voltage switch device and even the power system. Since the resistance value of the contact contact resistance of the high-voltage switch device is usually micro-ohm level, the value is very small, and the measurement result of the contact contact resistance becomes the key to studying the contact electric contact state.

[0003] At present, the measurement of the contact contact resistance is mostly carried out by a tester based on the direct current small current method. This tester applies a direct current small current to the contact contact resistance to calculate the resistance value of the contact contact resistance. However, the current amplitude applied by this tester is small, which cannot truly reflect the actual high-current environment of the high-voltage switch device, and the small current amplitude applied will affect the measurement result due to the film resistance of the oxidation film and the contamination film on the surface of the contact. All these lead to inaccurate measurement of the contact contact resistance. In addition, there are also testers based on the pulse current method for detection. Although this tester can apply a high-amplitude pulse current, the testers based on the pulse current method at present mostly use ordinary capacitors, which have limited capacity and low charging and discharging efficiency, and are difficult to meet the actual demand for pulse current. Moreover, the control stability of the current of the current tester is poor, which makes it difficult to apply more accurate pulse current to the contact contact resistance, thereby leading to inaccurate detection of the contact contact resistance. Therefore, there is an urgent need for a switch device contact contact resistance tester to solve the defects of the prior art. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a switch device contact contact resistance tester to solve the problem of inaccurate measurement of the contact contact resistance in the prior art and improve the accuracy of the measurement of the contact contact resistance.

[0005] To solve the above technical problems, the utility model embodiment provides a switch device contact contact resistance tester, which comprises a super capacitor module, a voltage sampling scaling module, a current sampling module, a super capacitor charging module, a pulse current control module and a data processing module.

[0006] The contact voltage sampling end of the voltage sampling scaling module is electrically connected with the contact contact resistance; the capacitance voltage sampling end of the voltage sampling scaling module is electrically connected with the voltage sampling end of the super capacitor module; the sampling voltage output end of the voltage sampling scaling module is electrically connected with the sampling voltage input end of the data processing module;

[0007] The first current loop end of the current sampling module is electrically connected with the first pulse current loop end of the super capacitor module; the second current loop end of the current sampling module is electrically connected with the contact contact resistance; the sampling current output end of the current sampling module is electrically connected with the sampling current input end of the data processing module;

[0008] The charging voltage output end of the super capacitor charging module is electrically connected with the charging voltage input end of the super capacitor module; the second pulse current loop end of the super capacitor module is electrically connected with the first end of the pulse current control module; the second end of the pulse current control module is electrically connected with the contact contact resistance;

[0009] The charging control signal output end of the data processing module is electrically connected with the charging control signal input end of the super capacitor charging module; the current control signal output end of the data processing module is electrically connected with the current control signal input end of the pulse current control module; the voltage amplification control signal output end of the data processing module is electrically connected with the voltage amplification control signal input end of the voltage sampling scaling module.

[0010] It can be understood that the utility model discloses through the electric connection between super capacitor module, voltage sampling zoom module, current sampling module, super capacitor charging module, pulse current control module and data processing module, through the charging of super capacitor charging module to super capacitor module, so that super capacitor module can charge super capacitor, and then through the control of pulse current control module to super capacitor, generates pulse current, so that the stable big pulse current can be applied to contact contact resistance, and the voltage and current of contact contact resistance are sampled through voltage sampling zoom module and current sampling module, then the detection of contact contact resistance is realized through data processing module. The utility model discloses through super capacitor module and super capacitor charging module can provide stable pulse current, avoids the pulse current instability and the low efficiency of pulse current charge-discharge caused by the ordinary capacitor in the prior art, through the connection between voltage sampling zoom module and super capacitor module, the voltage condition of super capacitor module can be monitored, so that the charging of super capacitor charging module to super capacitor module is adjusted more accurately based on actual test demand, and then it is ensured that super capacitor module can discharge more accurate and stable pulse current, then the current and voltage of contact contact resistance are collected through voltage sampling zoom module and current sampling module, and the test result of contact contact resistance can be obtained, not only accurate and stable pulse current can be provided, but also the influence of film resistance such as oxidation film, pollution film on the surface of contact on the measurement result can be avoided, and the accuracy of contact contact resistance measurement is improved.

[0011] As a preferred scheme, the voltage sampling zoom module comprises: a contact voltage sampling amplification unit and a capacitor voltage sampling reduction unit; the voltage sampling end of the contact voltage sampling amplification unit is the contact voltage sampling end of the voltage sampling zoom module, and is electrically connected with the contact contact resistance; the voltage sampling end of the capacitor voltage sampling reduction unit is the capacitor voltage sampling end of the voltage sampling zoom module, and is electrically connected with the voltage sampling end of the super capacitor module; the voltage amplification control signal input end of the contact voltage sampling amplification unit is the voltage amplification control signal input end of the voltage sampling zoom module; and the voltage sampling output end of the contact voltage sampling amplification unit and the voltage sampling output end of the capacitor voltage sampling reduction unit are both the sampling voltage output end of the voltage sampling zoom module.

[0012] The preferred embodiment can more accurately control the charging of the super capacitor module by the super capacitor charging module through the contact voltage sampling amplification unit and the capacitor voltage sampling reduction unit sampling the voltage of the super capacitor module, thereby ensuring that the pulse current generated by the super capacitor module is more stable and can meet the actual test requirements, so that the voltage measured by the contact voltage sampling amplification unit on the contact resistance is more accurate, and the accuracy of the contact resistance measurement is improved.

[0013] As a preferred embodiment, the contact voltage sampling amplification unit specifically comprises: a digital control gain instrument amplifier, an eleventh resistor, a ninth resistor, a nineteenth resistor, a twentieth resistor, a thirty-ninth resistor, a forty-third resistor, a forty-first resistor, a twenty-first resistor, a thirty-sixth resistor, a fortieth resistor, a forty-second resistor, a forty-fourth resistor, a fourth capacitor, an eleventh capacitor, a twelfth capacitor, a fifth capacitor, a sixth capacitor, a thirteenth capacitor, a fifteenth capacitor, a sixteenth capacitor, a second RF coaxial connector, a sixth diode, a seventh diode, an eighth diode, a twelfth diode, a third triode, and a fourth triode.

[0014] The third end of the second radio frequency coaxial connector is electrically connected with the second end of the eleventh resistor; the first end of the eleventh resistor is electrically connected with the second end of the ninth resistor; the first end of the ninth resistor is grounded; the fifth end of the second radio frequency coaxial connector is electrically connected with the first end of the nineteenth resistor; the second end of the nineteenth resistor is electrically connected with the first end of the twentieth resistor; the second end of the twentieth resistor is grounded; the first end of the fourth capacitor is grounded; the second end of the fourth capacitor is electrically connected with the second end of the ninth resistor; the first end of the twelfth capacitor is electrically connected with the first end of the twentieth resistor; the second end of the twelfth capacitor is grounded; the first end of the eleventh capacitor is electrically connected with the second end of the fourth capacitor; the second end of the eleventh capacitor is electrically connected with the first end of the twelfth capacitor; the anode of the sixth diode is electrically connected with the second end of the ninth resistor; the cathode of the seventh diode is electrically connected with the second end of the ninth resistor; the anode of the eighth diode is electrically connected with the first end of the twentieth resistor; the cathode of the twelfth diode is electrically connected with the first end of the twentieth resistor; the emitter of the thirteenth triode is electrically connected with the first end of the forty-third resistor; the collector of the thirteenth triode is grounded; the base of the thirteenth triode is electrically connected with the second end of the thirty-ninth resistor; the first end of the forty-first resistor is electrically connected with the base of the thirteenth triode; the second end of the forty-first resistor is grounded; the emitter of the fourth triode is electrically connected with the first end of the forty-fourth resistor; the collector of the fourth triode is grounded; the base of the fourth triode is electrically connected with the second end of the forty-first resistor; the first end of the forty-second resistor is electrically connected with the base of the fourth triode; the second end of the forty-second resistor is grounded; the fourth pin of the digital control gain instrument amplifier is electrically connected with the emitter of the thirteenth triode; the fifth pin of the digital control gain instrument amplifier is electrically connected with the emitter of the fourth triode; the first pin of the digital control gain instrument amplifier is electrically connected with the first end of the eleventh resistor; the tenth pin of the digital control gain instrument amplifier is electrically connected with the second end of the nineteenth resistor; the second pin of the digital control gain instrument amplifier is grounded; the ninth pin of the digital control gain instrument amplifier is grounded; the third pin of the digital control gain instrument amplifier is electrically connected with the first end of the fifth capacitor; the second end of the fifth capacitor is grounded; the third pin of the digital control gain instrument amplifier is electrically connected with the first end of the sixth capacitor; the second end of the sixth capacitor is grounded; the eighth pin of the digital control gain instrument amplifier is electrically connected with the first end of the fifteenth capacitor; the second end of the fifteenth capacitor is grounded; the eighth pin of the digital control gain instrument amplifier is electrically connected with the first end of the sixteenth capacitor; the second end of the sixteenth capacitor is grounded; the seventh pin of the digital control gain instrument amplifier is electrically connected with the first end of the twenty-first resistor;The second end of the twenty-first resistor is electrically connected with the first end of the thirteenth capacitor; the second end of the thirteenth capacitor is electrically connected with the second end of the thirty-sixth resistor; the first end of the thirty-sixth resistor is grounded; the second end of the thirteenth capacitor is grounded; the second end of the twenty-first resistor is grounded; the negative electrode of the sixth diode serves as a power supply interface of the contact voltage sampling and amplifying unit; the positive electrode of the seventh diode serves as a power supply interface of the contact voltage sampling and amplifying unit; the negative electrode of the eighth diode serves as a power supply interface of the contact voltage sampling and amplifying unit; the positive electrode of the twelfth diode serves as a power supply interface of the contact voltage sampling and amplifying unit; the second end of the forty-third resistor serves as a power supply interface of the contact voltage sampling and amplifying unit; the second end of the forty-fourth resistor serves as a power supply interface of the contact voltage sampling and amplifying unit; the first end of the fifth capacitor serves as a power supply interface of the contact voltage sampling and amplifying unit; the first end of the sixth capacitor serves as a power supply interface of the contact voltage sampling and amplifying unit; the first end of the fifteenth capacitor serves as a power supply interface of the contact voltage sampling and amplifying unit; the first end of the sixteenth capacitor serves as a power supply interface of the contact voltage sampling and amplifying unit; the sixth pin of the digital control gain instrument amplifier serves as a power supply interface of the contact voltage sampling and amplifying unit; the first end of the thirty-ninth resistor serves as a current limiting control port of the contact voltage sampling and amplifying unit; the first end of the fourth zero resistor serves as a current limiting control port of the contact voltage sampling and amplifying unit; the fourth pin and the fifth pin of the digital control gain instrument amplifier both serve as voltage amplification control signal input ends of the contact voltage sampling and amplifying unit; the input end of the second radio frequency coaxial connector serves as a voltage sampling end of the contact voltage sampling and amplifying unit; and the seventh pin of the digital control gain instrument amplifier serves as a voltage sampling output end of the contact voltage sampling and amplifying unit.

[0015] The contact voltage sampling and amplifying unit can amplify the voltage through the digital control gain instrument amplifier therein, and the amplification multiple can be controlled through the digital control gain instrument amplifier, so that the voltage measurement value of the contact contact resistance can be adjusted according to actual test requirements, and the input protection and output protection of the contact voltage sampling and amplifying unit can be realized through the corresponding resistors, capacitors and current limiting control ports, thereby further ensuring the accuracy of the voltage measurement value of the contact contact resistance and improving the accuracy of the contact contact resistance measurement.

[0016] As a preferred solution, the capacitor voltage sampling and reduction unit specifically comprises a ninth radio frequency coaxial connector, a differential amplifier, a nineteenth capacitor, a fifty-ninth resistor, a thirty-fourth capacitor, a fifty-eighth resistor and a thirty-fifth capacitor.

[0017] The second end of the ninth radio frequency coaxial connector is electrically connected with the fifth pin of the differential amplifier; the fifth end of the ninth radio frequency coaxial connector is electrically connected with the second pin of the differential amplifier; the second pin of the differential amplifier is electrically connected with the sixth pin of the differential amplifier; the third pin of the differential amplifier is grounded; the fourth pin of the differential amplifier is electrically connected with the first end of the nineteenth capacitor; the second end of the nineteenth capacitor is grounded; the seventh pin of the differential amplifier is electrically connected with the second end of the thirty-fourth capacitor; the first end of the thirty-fourth capacitor is grounded; the sixth pin of the differential amplifier is electrically connected with the first end of the fifty-eighth resistor; the second end of the fifty-eighth resistor is electrically connected with the first end of the thirty-fifth capacitor; the second end of the thirty-fifth capacitor is electrically connected with the second end of the fifty-ninth resistor; the first end of the fifty-ninth resistor is grounded; the second end of the fifty-ninth resistor is grounded; the second end of the fifty-eighth resistor is grounded; the seventh pin of the differential amplifier is used as a power supply interface of the capacitor voltage sampling reduction unit; the fourth pin of the differential amplifier is used as a power supply interface of the capacitor voltage sampling reduction unit; the input end of the ninth radio frequency coaxial connector is used as a voltage sampling end of the capacitor voltage sampling reduction unit; and the sixth pin of the differential amplifier is used as a voltage sampling output end of the capacitor voltage sampling reduction unit.

[0018] The capacitor voltage sampling reduction unit, in which the differential amplifier is arranged, can reduce the voltage collected by the super capacitor module, so that the collected super capacitor voltage is more accurate and meets the processing requirements of the data processing module, so that the voltage condition of the super capacitor module can be more accurately monitored, and the super capacitor charging module can be more accurately adjusted to charge the super capacitor module, so that the super capacitor module can discharge more accurate and stable pulse current, and the accuracy of the contact contact resistance measurement is improved.

[0019] As a preferred scheme, the super capacitor charging module specifically comprises a sixteenth optoelectrical coupler, an eighty-seventh resistor, a ninety-second resistor, a ninety-third resistor, a sixth transistor, a relay, a fourteenth diode, a power supply unit and a forty-eighth capacitor; a third end of the sixteenth optoelectrical coupler is electrically connected with a first end of the ninety-second resistor; a second end of the ninety-second resistor is electrically connected with a base of the sixth transistor; an emitter of the sixth transistor is electrically connected with a positive pole of the fourteenth diode; a collector of the sixth transistor is grounded; a first end of the ninety-third resistor is electrically connected with a second end of the ninety-second resistor; a second end of the ninety-third resistor is grounded; a first end of the sixteenth optoelectrical coupler is electrically connected with a first end of the eighty-seventh resistor; a second end of the sixteenth optoelectrical coupler is grounded; a second end of the relay is electrically connected with the positive pole of the fourteenth diode; a first end of the relay is electrically connected with a negative pole of the fourteenth diode; a fourth end of the relay is electrically connected with a first end of the power supply unit; a fifth end of the relay is electrically connected with a first end of the forty-eighth capacitor; a second end of the forty-eighth capacitor is electrically connected with a second end of the power supply unit; a fourth end of the sixteenth optoelectrical coupler serves as a power supply interface of the super capacitor charging module; the negative pole of the fourteenth diode serves as a power supply interface of the super capacitor charging module; the first end and the second end of the power supply unit both serve as a charging voltage output end of the super capacitor charging module; and the second end of the eighty-seventh resistor serves as a charging control signal input end of the super capacitor charging module.

[0020] The super capacitor charging module in the preferred scheme can realize accurate charging control of the super capacitor module through the combination of the sixteenth optoelectrical coupler, the resistor and the capacitor, thereby ensuring that the super capacitor module can generate accurate and stable pulse current, and further improving the accuracy of the contact contact resistance measurement.

[0021] As a preferred scheme, the pulse current control module specifically comprises the eighty-sixth resistor, the ninetieth resistor, the seventeenth optocoupler, the forty-sixth capacitor, the ninety-ninth resistor, the twenty-third drive control chip, the one-hundredth resistor, the fifty-second capacitor, the ninety-seventh resistor, the thirteenth diode, the twentieth MOS tube, the tenth diode, the ninety-fourth resistor, the fifth transistor, the ninety-first resistor, the eighty-ninth resistor, the eleventh diode, a pulse inductor, the fifteenth diode, the seventeenth diode, the forty-ninth capacitor and the eighth thyristor; the first end of the eighty-sixth resistor is grounded; the second end of the eighty-sixth resistor is electrically connected with the first end of the ninetieth resistor; the second end of the ninetieth resistor is electrically connected with the first end of the seventeenth optocoupler; the second end of the seventeenth optocoupler is grounded; the third end of the seventeenth optocoupler is grounded; the fourth end of the seventeenth optocoupler is electrically connected with the first pin of the twenty-third drive control chip; the fourth end of the seventeenth optocoupler is electrically connected with the first end of the forty-sixth capacitor; the second end of the forty-sixth capacitor is electrically connected with the second pin of the twenty-third drive control chip; the second end of the forty-sixth capacitor is electrically connected with the first end of the ninety-ninth resistor; the second end of the ninety-ninth resistor is electrically connected with the first end of the one-hundredth resistor; the seventh pin of the twenty-third drive control chip is electrically connected with the first end of the one-hundredth resistor; the sixth pin of the twenty-third drive control chip is electrically connected with the second end of the forty-sixth capacitor; the fifth pin of the twenty-third drive control chip is electrically connected with the first end of the fifty-second capacitor; the second end of the fifty-second capacitor is electrically connected with the first end of the forty-sixth capacitor; the third pin of the twenty-third drive control chip is electrically connected with the negative electrode of the eleventh diode; the positive electrode of the eleventh diode is grounded; the negative electrode of the eleventh diode is electrically connected with the first end of the eighty-ninth resistor; the second end of the eighty-ninth resistor is electrically connected with the base of the fifth transistor; the collector of the fifth transistor is grounded; the emitter of the fifth transistor is electrically connected with the second end of the ninety-first resistor; the first end of the ninety-fourth resistor is electrically connected with the second end of the ninety-first resistor; the second end of the ninety-fourth resistor is grounded; the first end of the tenth diode is electrically connected with the second end of the ninety-first resistor; the second end of the tenth diode is grounded; the gate of the twentieth MOS tube is electrically connected with the second end of the ninety-first resistor; the source of the twentieth MOS tube is grounded; the drain of the twentieth MOS tube is electrically connected with the positive electrode of the thirteenth diode; the negative electrode of the thirteenth diode is electrically connected with the second end of the ninety-seventh resistor; the first end of the pulse inductor is electrically connected with the second end of the ninety-seventh resistor; the second end of the pulse inductor is electrically connected with the positive electrode of the thirteenth diode; the third end of the pulse inductor is electrically connected with the positive electrode of the fifteenth diode.The fourth end of the pulse inductor is electrically connected with the anode of the seventeenth diode; the cathode of the fifteenth diode is electrically connected with the cathode of the seventeenth diode; the gate of the eighth thyristor is electrically connected with the cathode of the fifteenth diode; the cathode of the eighth thyristor is electrically connected with the first end of the forty-ninth capacitor; the anode of the eighth thyristor serves as the first end of the pulse current control module; the second end of the forty-ninth capacitor serves as the second end of the pulse current control module; the second end of the eighty-sixth resistor serves as the current control signal input end of the pulse current control module; the fourth pin of the twenty-third drive control chip serves as the power supply interface of the pulse current control module; the eighth pin of the twenty-third drive control chip serves as the power supply interface of the pulse current control module; the second end of the first hundred resistor serves as the power supply interface of the pulse current control module; the first end of the ninety-first resistor serves as the power supply interface of the pulse current control module; and the first end of the ninety-seventh resistor serves as the power supply interface of the pulse current control module.

[0022] The eighth thyristor, the twenty-third drive control chip, the seventeenth optoelectronic coupler, the resistor and the capacitor are combined in the pulse current control module, so that the discharge of the super capacitor module can be controlled, the pulse current released by the super capacitor module is more accurate and stable, the actual high current environment of the high-voltage switch device can be truly reflected, the influence of the film resistance such as the oxidation film and the pollution film on the contact surface on the measurement result can be avoided, and the accuracy of the contact resistance measurement is improved.

[0023] As a preferred solution, the super capacitor module is a super capacitor group; the super capacitor group comprises a plurality of super capacitors connected in series; the anode of the super capacitor group serves as the first pulse current loop end of the super capacitor module; the cathode of the super capacitor group serves as the second pulse current loop end of the super capacitor module; the anode and the cathode of the super capacitor group both serve as the voltage sampling end of the super capacitor module; and the anode and the cathode of the super capacitor group both serve as the charging voltage input end of the super capacitor module.

[0024] Compared with the ordinary capacitor used in the prior art, the plurality of super capacitors connected in series can generate a more stable, more accurate and larger-amplitude pulse current, so that the actual high current environment of the high-voltage switch device can be truly reflected, and the accuracy of the contact resistance measurement is improved.

[0025] As a preferred solution, the data processing module comprises: an ADC / DAC converter and an FPGA data processing chip; a current input end of the ADC / DAC converter serves as a sampling current input end of the data processing module; a voltage input end of the ADC / DAC converter serves as a sampling voltage input end of the data processing module; a data output end of the ADC / DAC converter is electrically connected with a data input end of the FPGA data processing chip; a current control signal output end of the FPGA data processing chip serves as a current control signal output end of the data processing module; a charging control signal output end of the FPGA data processing chip serves as a charging control signal output end of the data processing module; and a voltage amplification control signal output end of the FPGA data processing chip serves as a voltage amplification control signal output end of the data processing module.

[0026] The combination of the ADC / DAC converter and the FPGA data processing chip can not only control the charging of the super capacitor module by the super capacitor charging module, but also control the generation of the pulse current of the super capacitor module by the pulse current control module, so that more accurate and stable pulse current can be generated, and the collected voltage and current of the contact contact resistance can be processed, thereby realizing accurate measurement of the contact contact resistance.

[0027] As a preferred solution, the switch device contact contact resistance tester further comprises a display module; the display module comprises: a touch screen, a data export unit, a test control knob and a state indicating lamp; an input end of the data export unit is electrically connected with a data output end of the FPGA data processing chip; a control instruction output end of the test control knob is electrically connected with a control instruction input end of the FPGA data processing chip; a data input end of the touch screen is electrically connected with a data output end of the FPGA data processing chip; and an input end of the state indicating lamp is electrically connected with a working state output end of the FPGA data processing chip.

[0028] The touch screen, the data export unit, the test control knob and the state indicating lamp can better adapt to the measurement of the contact contact resistance in different scenes, and the process of measurement can be adjusted and controlled, thereby improving the accuracy and applicability of the contact contact resistance.

[0029] As a preferred solution, the switch device contact contact resistance tester further comprises a tester shell; the super capacitor module, the voltage sampling scaling module, the current sampling module, the super capacitor charging module, the pulse current control module and the data processing module are arranged inside the tester shell; and the display module is arranged on an upper surface of the tester shell.

[0030] The preferred scheme can ensure stable and safe operation of the super capacitor module, the voltage sampling zoom module, the current sampling module, the super capacitor charging module, the pulse current control module and the data processing module by arranging the tester housing, and the display module on the upper surface of the tester housing is used for regulating and controlling the test, thereby improving the accuracy and stability of the contact contact resistance measurement. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 A module connection schematic diagram of the switch device contact contact resistance tester is provided for the embodiments of the utility model;

[0032] Figure 2 A connection schematic diagram of a contact voltage sampling amplification unit is provided for the embodiments of the utility model;

[0033] Figure 3 A connection schematic diagram of a capacitor voltage sampling zooming unit is provided for the embodiments of the utility model;

[0034] Figure 4 A connection schematic diagram of a super capacitor charging module is provided for the embodiments of the utility model;

[0035] Figure 5 A connection schematic diagram of a pulse current control module is provided for the embodiments of the utility model;

[0036] Figure 6 An equivalent model of the contact contact resistance is provided for the embodiments of the utility model;

[0037] Figure 7 A change rate schematic diagram of the pulse current is provided for the embodiments of the utility model;

[0038] Figure 8 A pulse current generation circuit schematic diagram of another tester is provided for the embodiments of the utility model;

[0039] Figure 9 A structure schematic diagram of another tester is provided for the embodiments of the utility model. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0041] Embodiment one

[0042] To solve the problem of inaccurate contact contact resistance measurement in the prior art, please refer to Figure 1 The utility model provides a kind of module connection schematic diagram of switchgear contact contact resistance tester provided in the embodiment of the utility model;It is suitable for contact contact resistance 107, comprising: super capacitor module 101, voltage sampling zoom module 102, current sampling module 103, super capacitor charging module 104, pulse current control module 105 and data processing module 106;

[0043] The contact voltage sampling end of the voltage sampling zoom module is electrically connected with the contact contact resistance;The capacitor voltage sampling end of the voltage sampling zoom module is electrically connected with the voltage sampling end of the super capacitor module;The sampling voltage output end of the voltage sampling zoom module is electrically connected with the sampling voltage input end of the data processing module;

[0044] The first current loop end of the current sampling module is electrically connected with the first pulse current loop end of the super capacitor module;The second current loop end of the current sampling module is electrically connected with the contact contact resistance;The sampling current output end of the current sampling module is electrically connected with the sampling current input end of the data processing module;

[0045] The charging voltage output end of the super capacitor charging module is electrically connected with the charging voltage input end of the super capacitor module;The second pulse current loop end of the super capacitor module is electrically connected with the first end of the pulse current control module;The second end of the pulse current control module is electrically connected with the contact contact resistance;

[0046] The charging control signal output end of the data processing module is electrically connected with the charging control signal input end of the super capacitor charging module;The current control signal output end of the data processing module is electrically connected with the current control signal input end of the pulse current control module;The voltage amplification control signal output end of the data processing module is electrically connected with the voltage amplification control signal input end of the voltage sampling zoom module.

[0047] In the embodiment, the voltage sampling zoom module comprises: a contact voltage sampling amplification unit and a capacitor voltage sampling reduction unit;

[0048] The voltage sampling end of the contact voltage sampling amplification unit serves as the contact voltage sampling end of the voltage sampling zoom module, and is electrically connected with the contact contact resistance;

[0049] The voltage sampling end of the capacitor voltage sampling reduction unit serves as the capacitor voltage sampling end of the voltage sampling zoom module, and is electrically connected with the voltage sampling end of the super capacitor module;

[0050] The voltage amplification control signal input end of the contact voltage sampling amplification unit serves as the voltage amplification control signal input end of the voltage sampling scaling module.

[0051] The voltage sampling output end of the contact voltage sampling amplification unit and the voltage sampling output end of the capacitor voltage sampling reduction unit both serve as the sampling voltage output end of the voltage sampling scaling module.

[0052] The contact voltage sampling amplification unit and the capacitor voltage sampling reduction unit are used to sample the voltage of the super capacitor module by the capacitor voltage sampling reduction unit, so that the charging of the super capacitor module by the super capacitor charging module can be more accurately controlled, the pulse current generated by the super capacitor module is more stable, and the actual test requirements can be met, so that the voltage measured by the contact voltage sampling amplification unit on the contact contact resistance is more accurate, and the accuracy of the contact contact resistance measurement is improved.

[0053] In the embodiment, refer to Figure 2 A connection diagram of a contact voltage sampling amplification unit is provided in the embodiment of the utility model, the contact voltage sampling amplification unit specifically comprises: a numerical control gain instrument amplifier U7, an eleventh resistor R11, a ninth resistor R9, a nineteenth resistor R19, a twentieth resistor R20, a thirty-ninth resistor R39, a forty-third resistor R43, a forty-first resistor R41, a twenty-first resistor R21, a thirty-sixth resistor R36, a fortieth resistor R40, a forty-second resistor R42, a forty-fourth resistor R44, a fourth capacitor C4, an eleventh capacitor C11, a twelfth capacitor C12, a fifth capacitor C5, a sixth capacitor C6, a thirteenth capacitor C13, a fifteenth capacitor C15, a sixteenth capacitor C16, a second radio frequency coaxial connector RF2, a sixth diode D6, a seventh diode D7, an eighth diode D8, a twelfth diode D10, a third triode Q3 and a fourth triode Q4.

[0054] The third end of the second radio frequency coaxial connector RF2 is electrically connected with the second end of the eleventh resistor R11; the first end of the eleventh resistor R11 is electrically connected with the second end of the ninth resistor R9; the first end of the ninth resistor R9 is grounded; the fifth end of the second radio frequency coaxial connector RF2 is electrically connected with the first end of the nineteenth resistor R19; the second end of the nineteenth resistor R19 is electrically connected with the first end of the twentieth resistor R20; the second end of the twentieth resistor R20 is grounded; the first end of the fourth capacitor C4 is grounded; the second end of the fourth capacitor C4 is electrically connected with the second end of the ninth resistor R9; the first end of the twelfth capacitor C12 is electrically connected with the first end of the twentieth resistor R20; the second end of the twelfth capacitor C12 is grounded; the first end of the eleventh capacitor C11 is electrically connected with the second end of the fourth capacitor C4; the second end of the eleventh capacitor C11 is electrically connected with the first end of the twelfth capacitor C12; the anode of the sixth diode D6 is electrically connected with the second end of the ninth resistor R9; the cathode of the seventh diode D7 is electrically connected with the second end of the ninth resistor R9; the anode of the eighth diode D8 is electrically connected with the first end of the twentieth resistor R20; the cathode of the twelfth diode D10 is electrically connected with the first end of the twentieth resistor R20; the emitter of the third transistor Q3 is electrically connected with the first end of the forty-third resistor R43; the collector of the third transistor Q3 is grounded; the base of the third transistor Q3 is electrically connected with the second end of the thirty-ninth resistor R39; the first end of the forty-first resistor R41 is electrically connected with the base of the third transistor Q3; the second end of the forty-first resistor R41 is grounded; the emitter of the fourth transistor Q4 is electrically connected with the first end of the forty-fourth resistor R44; the collector of the fourth transistor Q4 is grounded; the base of the fourth transistor Q4 is electrically connected with the second end of the fortieth resistor R40; the first end of the forty-second resistor R42 is electrically connected with the base of the fourth transistor Q4; the second end of the forty-second resistor R42 is grounded; the fourth pin of the digital gain instrument amplifier U7 is electrically connected with the emitter of the third transistor Q3; the fifth pin of the digital gain instrument amplifier U7 is electrically connected with the emitter of the fourth transistor Q4; the first pin of the digital gain instrument amplifier U7 is electrically connected with the first end of the eleventh resistor R11; the tenth pin of the digital gain instrument amplifier U7 is electrically connected with the second end of the nineteenth resistor R19; the second pin of the digital gain instrument amplifier U7 is grounded; the ninth pin of the digital gain instrument amplifier U7 is grounded; the third pin of the digital gain instrument amplifier U7 is electrically connected with the first end of the fifth capacitor C5; the second end of the fifth capacitor C5 is grounded; the third pin of the digital gain instrument amplifier U7 is electrically connected with the first end of the sixth capacitor C6; the second end of the sixth capacitor C6 is grounded.The eighth pin of the digital gain instrument amplifier U7 is electrically connected with the first end of the fifteenth capacitor C15; the second end of the fifteenth capacitor C15 is grounded; the eighth pin of the digital gain instrument amplifier U7 is electrically connected with the first end of the sixteenth capacitor C16; the second end of the sixteenth capacitor C16 is grounded; the seventh pin of the digital gain instrument amplifier U7 is electrically connected with the first end of the twenty-first resistor R21; the second end of the twenty-first resistor R21 is electrically connected with the first end of the thirteenth capacitor C13; the second end of the thirteenth capacitor C13 is electrically connected with the second end of the thirty-sixth resistor R36; the first end of the thirty-sixth resistor R36 is grounded; the second end of the thirteenth capacitor C13 is grounded; the second end of the twenty-first resistor R21 is grounded; the negative electrode of the sixth diode D6 serves as a power supply interface of the contact voltage sampling and amplifying unit; the positive electrode of the seventh diode D7 serves as a power supply interface of the contact voltage sampling and amplifying unit; the negative electrode of the eighth diode D8 serves as a power supply interface of the contact voltage sampling and amplifying unit; the positive electrode of the twelfth diode D10 serves as a power supply interface of the contact voltage sampling and amplifying unit; the second end of the forty-third resistor R43 serves as a power supply interface of the contact voltage sampling and amplifying unit; the second end of the forty-fourth resistor R44 serves as a power supply interface of the contact voltage sampling and amplifying unit; the first end of the fifth capacitor C5 serves as a power supply interface of the contact voltage sampling and amplifying unit; the first end of the sixth capacitor C6 serves as a power supply interface of the contact voltage sampling and amplifying unit; the first end of the fifteenth capacitor C15 serves as a power supply interface of the contact voltage sampling and amplifying unit; the first end of the sixteenth capacitor C16 serves as a power supply interface of the contact voltage sampling and amplifying unit; the sixth pin of the digital gain instrument amplifier U7 serves as a power supply interface of the contact voltage sampling and amplifying unit; the first end of the thirty-ninth resistor R39 serves as a current limiting control port of the contact voltage sampling and amplifying unit; the first end of the fortieth resistor R40 serves as a current limiting control port of the contact voltage sampling and amplifying unit; the fourth pin and the fifth pin of the digital gain instrument amplifier U7 both serve as voltage amplification control signal input ends of the contact voltage sampling and amplifying unit; the input end of the second radio frequency coaxial connector RF2 serves as a voltage sampling end of the contact voltage sampling and amplifying unit; the seventh pin of the digital gain instrument amplifier U7 serves as a voltage sampling output end of the contact voltage sampling and amplifying unit.

[0055] In an alternative embodiment, as Figure 2The model of the digital control gain instrument amplifier U7 in the contact voltage sampling amplification unit is AD8253, and the model of the second radio frequency coaxial connector RF2 is BWSMA-KE-P001;The models of the sixth diode D6, the seventh diode D7, the eighth diode D8 and the twelfth diode D10 are all SD101, and the models of the third triode Q3 and the fourth triode Q4 are both SS8050;

[0056] It should be noted that the contact contact resistance is generally only a few tens of mu omega, in order to further improve the voltage drop generated by the pulse current, improve the signal-to-noise ratio of the voltage, and realize accurate measurement of the weak signal, it is necessary to use a voltage amplification circuit to amplify the signal, because the pulse current amplitude range is large (0-3200A), in order to make the amplified voltage not exceed the sampling range of the subsequent data processing module, the current with smaller amplitude should be amplified by a larger amplification factor, and the current with higher amplitude should be amplified by a smaller amplification factor;

[0057] Specifically, the working principle of the contact voltage sampling amplification unit is as follows: the voltage of the contact contact resistance is obtained through the second radio frequency coaxial connector RF2, then the fourth pin and the fifth pin (i.e. A0, A1) of the digital control gain instrument amplifier U7 are used to control the voltage amplification factor (including 1, 10, 100, 1000), so as to realize different multiple amplification of the voltage, the selection of the amplification factor can be controlled by the data processing module, and the circuit protection and output protection of the contact voltage sampling amplification unit are realized by the capacitor and the resistor, that is, the devices in the contact voltage sampling amplification unit are not wasted, and the voltage input to the data processing module is within its processing range.

[0058] The contact voltage sampling amplification unit in the embodiment can amplify the voltage through the digital control gain instrument amplifier, and control the amplification factor through the digital control gain instrument amplifier, so that the voltage measurement value of the contact contact resistance is more accurate, and the input protection and output protection of the contact voltage sampling amplification unit can be realized through the corresponding resistor, capacitor and current limiting control port, so as to further ensure the accuracy of the voltage measurement value of the contact contact resistance and improve the accuracy of the contact contact resistance measurement.

[0059] In the embodiment, please refer to Figure 3 The connection schematic diagram of the capacitor voltage sampling reduction unit provided in the embodiment of the utility model, the capacitor voltage sampling reduction unit, specifically comprises: the ninth radio frequency coaxial connector RF9, the differential amplifier U11, the nineteenth capacitor C19, the fifty-ninth resistor R59, the thirty-fourth capacitor C34, the fifty-eighth resistor R58 and the thirty-fifth capacitor C35;

[0060] The second end of the ninth radio frequency coaxial connector RF9 is electrically connected with the fifth pin of the differential amplifier U11; the fifth end of the ninth radio frequency coaxial connector RF9 is electrically connected with the second pin of the differential amplifier U11; the second pin of the differential amplifier U11 is electrically connected with the sixth pin of the differential amplifier U11; the third pin of the differential amplifier U11 is grounded; the fourth pin of the differential amplifier U11 is electrically connected with the first end of the nineteenth capacitor C19; the second end of the nineteenth capacitor C19 is grounded; the seventh pin of the differential amplifier U11 is electrically connected with the second end of the thirty-fourth capacitor C34; the first end of the thirty-fourth capacitor C34 is grounded; the sixth pin of the differential amplifier U11 is electrically connected with the first end of the fifty-eighth resistor R58; the second end of the fifty-eighth resistor R58 is electrically connected with the first end of the thirty-fifth capacitor C35; the second end of the thirty-fifth capacitor C35 is electrically connected with the second end of the fifty-ninth resistor R59; the first end of the fifty-ninth resistor R59 is grounded; the second end of the fifty-ninth resistor R59 is grounded; the second end of the fifty-eighth resistor R58 is grounded; the seventh pin of the differential amplifier U11 serves as a power supply interface of the capacitor voltage sampling and reduction unit; the fourth pin of the differential amplifier U11 serves as a power supply interface of the capacitor voltage sampling and reduction unit; the input end of the ninth radio frequency coaxial connector RF9 serves as a voltage sampling end of the capacitor voltage sampling and reduction unit; and the sixth pin of the differential amplifier U11 serves as a voltage sampling output end of the capacitor voltage sampling and reduction unit.

[0061] In an optional embodiment, the ninth radio frequency coaxial connector RF9 is of the model BWSMA-KE-P001, and the differential amplifier U11 is of the model INA143, and has an input impedance greater than 1MΩ and an accuracy of ±0.1%.

[0062] Since the current amplitude of the pulse current can be controlled by detecting the charging voltage of the super capacitor module, the capacitance voltage of the super capacitor module needs to be sampled, and the rated voltage of the super capacitor module is large (the rated voltage of the super capacitor module provided in the embodiment is 32.4V), while the maximum input voltage that can be received by the data processing module is small (10V in the embodiment), so the capacitance voltage needs to be reduced. Moreover, since the common-mode voltage in the tester is generally 30V, the differential-mode signal problem caused thereby also needs to be handled. Therefore, the working principle of the capacitor voltage sampling and reduction unit in the embodiment is specifically as follows: the voltage of the super capacitor module is sampled through the ninth radio frequency coaxial connector RF9, and then reduced by 10 times through the differential amplifier U11 (of the model INA143).

[0063] The embodiment realizes the voltage collected by the super capacitor module through the differential amplifier in the capacitor voltage sampling reduction unit, can ensure that the collected super capacitor voltage is more accurate and meets the processing requirements of the data processing module, thereby more accurately monitoring the voltage condition of the super capacitor module, and more accurately adjusting the charging of the super capacitor charging module to the super capacitor module, thereby ensuring that the super capacitor module can discharge more accurate and stable pulse current, and improving the accuracy of the contact contact resistance measurement.

[0064] In the embodiment, refer to Figure 4 A connection diagram of a super capacitor charging module is provided in the embodiment of the utility model, and the super capacitor charging module specifically comprises: a sixteenth optoelectronic coupler U16, an eighty-seventh resistor R87, a ninety-second resistor R92, a ninety-third resistor R93, a sixth triode Q6, a relay K2, a fourteenth diode D14, a power supply unit and a forty-eighth capacitor C48.

[0065] The third end of the sixteenth optoelectronic coupler U16 is electrically connected with the first end of the ninety-second resistor R92; the second end of the ninety-second resistor R92 is electrically connected with the base of the sixth triode Q6; the emitter of the sixth triode Q6 is electrically connected with the anode of the fourteenth diode D14; the collector of the sixth triode Q6 is grounded; the first end of the ninety-third resistor R93 is electrically connected with the second end of the ninety-second resistor R92; the second end of the ninety-third resistor R93 is grounded; the first end of the sixteenth optoelectronic coupler U16 is electrically connected with the first end of the eighty-seventh resistor R87; the second end of the sixteenth optoelectronic coupler U16 is grounded; the second end of the relay K2 is electrically connected with the anode of the fourteenth diode D14; the first end of the relay K2 is electrically connected with the cathode of the fourteenth diode D14; the fourth end of the relay K2 is electrically connected with the first end of the power supply unit; the fifth end of the relay K2 is electrically connected with the first end of the forty-eighth capacitor C48; the second end of the forty-eighth capacitor C48 is electrically connected with the second end of the power supply unit; the fourth end of the sixteenth optoelectronic coupler U16 serves as a power supply interface of the super capacitor charging module; the cathode of the fourteenth diode D14 serves as a power supply interface of the super capacitor charging module; the first end and the second end of the power supply unit both serve as a charging voltage output end of the super capacitor charging module; and the second end of the eighty-seventh resistor R87 serves as a charging control signal input end of the super capacitor charging module.

[0066] In an optional embodiment, the model of the sixteenth optoelectronic coupler U16 is EL817, and the model of the relay K2 is SLA-05VDC-SL-C; the power supply unit refers to Figure 425A, represents that the power supply unit provides 25A of current; the sixth transistor Q6 is SS8050; the fourteenth diode D14 is 1N4148W; the working principle of the super capacitor charging module is: collecting the voltage of the super capacitor module through the capacitor voltage sampling reduction unit described above, and then judging whether the super capacitor charging module needs to be disconnected from the super capacitor module or not, when it needs to be disconnected, making the CHARGE0 in Figure 2 low level, controlling the relay K2 and the sixth transistor Q6 to be in the off state, stopping the super capacitor charging module from charging the super capacitor module; when it needs to continue charging, making the CHARGE0 in Figure 2 high level, controlling the relay K2 and the sixth transistor Q6 to be in the on state, keeping the super capacitor charging module from charging the super capacitor module. In particular, another relay can also be set to completely isolate the super capacitor module from the super capacitor charging module when discharging.

[0067] The embodiment can realize accurate charging control of the super capacitor module through the super capacitor charging module, the combination of the relay, the sixteenth optoelectronic coupler, the resistor and the capacitor, so as to ensure that the super capacitor module can generate accurate and stable pulse current, and then improve the accuracy of the contact contact resistance measurement.

[0068] In the embodiment, please refer to Figure 5 , a connection diagram of a pulse current control module provided by the embodiment of the utility model; the pulse current control module, specifically includes: eighty-sixth resistor R86, ninetieth resistor R90, seventeenth optoelectronic coupler U17, forty-sixth capacitor C46, ninety-ninth resistor R99, twenty-third drive control chip U23, one hundredth resistor R100, fifty-second capacitor C52, ninety-seventh resistor R97, thirteenth diode D13, twentieth MOS tube U20, tenth diode D12, ninety-fourth resistor R94, fifth transistor Q5, ninety-first resistor R91, eighty-ninth resistor R89, eleventh diode D11, pulse inductor N, fifteenth diode D15, seventeenth diode D17, forty-ninth capacitor C49 and eighth thyristor Q8;

[0069] An eleventh resistor R11 has a first end connected to ground and a second end connected to a first end of a twelfth resistor R12. The second end of the twelfth resistor R12 is connected to a first end of a thirteenth resistor R13. The second end of the thirteenth resistor R13 is connected to a first end of a fourteenth resistor R14. The second end of the fourteenth resistor R14 is connected to a first end of a fifteenth resistor R15. The second end of the fifteenth resistor R15 is connected to a first end of a sixteenth resistor R16. The second end of the sixteenth resistor R16 is connected to a first end of a seventeenth resistor R17. The second end of the seventeenth resistor R17 is connected to a first end of an eighteenth resistor R18. The second end of the eighteenth resistor R18 is connected to a first end of a nineteenth resistor R19. The second end of the nineteenth resistor R19 is connected to a first end of a twentieth resistor R20. The second end of the twentieth resistor R20 is connected to a first end of a twenty-first resistor R21. The second end of the twenty-first resistor R21 is connected to a first end of a twenty-second resistor R22. The second end of the twenty-second resistor R22 is connected to a first end of a twenty-third resistor R23. The second end of the twenty-third resistor R23 is connected to a first end of a twenty-fourth resistor R24. The second end of the twenty-fourth resistor R24 is connected to a first end of a twenty-fifth resistor R25. The second end of the twenty-fifth resistor R25 is connected to a first end of a twenty-sixth resistor R26. The second end of the twenty-sixth resistor R26 is connected to a first end of a twenty-seventh resistor R27. The second end of the twenty-seventh resistor R27 is connected to a first end of a twenty-eighth resistor R28. The second end of the twenty-eighth resistor R28 is connected to a first end of a twenty-ninth resistor R29. The second end of the twenty-ninth resistor R29 is connected to a first end of a thirtieth resistor R30. The second end of the thirtieth resistor R30 is connected to a first end of a thirty-first resistor R31. The second end of the thirty-first resistor R31 is connected to a first end of a thirty-second resistor R32. The second end of the thirty-second resistor R32 is connected to a first end of a thirty-third resistor R33. The second end of the thirty-third resistor R33 is connected to a first end of a thirty-fourth resistor R34. The second end of the thirty-fourth resistor R34 is connected to a first end of a thirty-fifth resistor R35. The second end of the thirty-fifth resistor R35 is connected to a first end of a thirty-sixth resistor R36. The second end of the thirty-sixth resistor R36 is connected to a first end of a thirty-seventh resistor R37. The second end of the thirty-seventh resistor R37 is connected to a first end of a thirty-eighth resistor R38. The second end of the thirty-eighth resistor R38 is connected to a first end of a thirty-ninth resistor R39. The second end of the thirty-ninth resistor R39 is connected to a first end of a fortieth resistor R40. The second end of the fortieth resistor R40 is connected to a first end of a forty-first resistor R41. The second end of the forty-first resistor R41 is connected to a first end of a forty-second resistor R42. The second end of the forty-second resistor R42 is connected to a first end of a forty-third resistor R43. The second end of the forty-third resistor R43 is connected to a first end of a forty-fourth resistor R44. The second end of the forty-fourth resistor R44 is connected to a first end of a forty-fifth resistor R45. The second end of the forty-fifth resistor R45 is connected to a first end of a forty-sixth resistor R46. The second end of the forty-sixth resistor R46 is connected to a first end of a forty-seventh resistor R47. The second end of the forty-seventh resistor R47 is connected to a first end of a forty-eighth resistor R48. The second end of the forty-eighth resistor R48 is connected to a first end of a forty-ninth resistor R49. The second end of the forty-ninth resistor R49 is connected to a first end of a fiftieth resistor R50. The second end of the fiftieth resistor R50 is connected to a first end of a fifty-first resistor R51. The second end of the fifty-first resistor R51 is connected to a first end of a fifty-second resistor R52. The second end of the fifty-second resistor R52 is connected to a first end of a fifty-third resistor R53. The second end of the fifty-third resistor R53 is connected to a first end of a fifty-fourth resistor R54. The second end of the fifty-fourth resistor R54 is connected to a first end of a fifty-fifth resistor R55. The second end of the fifty-fifth resistor R55 is connected to a first end of a fifty-sixth resistor R56. The second end of the fifty-sixth resistor R56 is connected to a first end of a fifty-seventh resistor R57. The second end of the fifty-seventh resistor R57 is connected to a first end of a fifty-eighth resistor R58. The second end of the fifty-eighth resistor R58 is connected to a first end of a fifty-ninth resistor R59. The second end of the fifty-ninth resistor R59 is connected to a first end of a sixtieth resistor R60.The cathode of the fifteenth diode D15 is electrically connected to the cathode of the seventeenth diode D17; the gate of the eighth thyristor Q8 is electrically connected to the cathode of the fifteenth diode D15; the cathode of the eighth thyristor Q8 is electrically connected to the first terminal of the forty-ninth capacitor C49; the anode of the eighth thyristor Q8 serves as the first terminal of the pulse current control module; the second terminal of the forty-ninth capacitor C49 serves as the second terminal of the pulse current control module; the second terminal of the eighty-sixth resistor R86 serves as the current control signal input terminal of the pulse current control module; the fourth pin of the twenty-third drive control chip U23 serves as the power supply interface of the pulse current control module; the eighth pin of the twenty-third drive control chip U23 serves as the power supply interface of the pulse current control module; the second terminal of the first hundredth resistor R100 serves as the power supply interface of the pulse current control module; the first terminal of the ninety-first resistor R91 serves as the power supply interface of the pulse current control module; the first terminal of the ninety-seventh resistor R97 serves as the power supply interface of the pulse current control module.

[0070] In an optional embodiment, the eighth thyristor Q8 is a KP2000A with a maximum surge current of 25kA, requiring a trigger current of 40-300mA to conduct; the seventeenth optocoupler U17 is a PC817C; the twenty-third drive control chip U23 is an NE555; the twentieth MOSFET U20 is an IRF730; the twelfth diode D12, eleventh diode D11, fifteenth diode D15, and seventeenth diode D17 are all 1N4007; the fifth transistor Q5 is a 2N5551; and the pulse inductor is a 1:2 pulse inductor. The pulse current control module operates by: through several... The processing module controls the level of THYISTOR, which in turn controls the output pulse of the 23rd drive control chip U23 (NE555). When THYISTOR is high, the 23rd drive control chip U23 (NE555) outputs a square wave with a frequency of 1kHz, which triggers the 8th thyristor Q8 to conduct through the pulse inductor N, thereby allowing the current generated by the supercapacitor module to flow in the loop between the supercapacitor module and the contact resistance. When THYISTOR is low, the 23rd drive control chip U23 (NE555) outputs a high level, and the 8th thyristor Q8 is turned on and off, thus breaking the loop between the supercapacitor module and the contact resistance.

[0071] The eighth thyristor, the twenty-third drive control chip, the seventeenth photoelectric coupler, the resistor and the capacitor are combined to form a pulse current control module, so that the discharge of the super capacitor module can be controlled, the pulse current released by the super capacitor module is more accurate and stable, the actual high current environment of the high-voltage switch device can be truly reflected, the influence of the film resistance such as the oxidation film and the pollution film on the surface of the contact on the measurement result can be avoided, and the accuracy of the contact resistance measurement is improved.

[0072] In the embodiment, the super capacitor module is a super capacitor group, the super capacitor group includes a plurality of super capacitors connected in series, the positive electrode of the super capacitor group is used as the first pulse current loop end of the super capacitor module, the negative electrode of the super capacitor group is used as the second pulse current loop end of the super capacitor module, the positive electrode and the negative electrode of the super capacitor group are used as the voltage sampling ends of the super capacitor module, and the positive electrode and the negative electrode of the super capacitor group are used as the charging voltage input ends of the super capacitor module.

[0073] In an optional embodiment, the number of super capacitors is 12, the rated voltage of the super capacitors is 2.7 V, the single capacity of the super capacitors is 3000 F, and the model of the super capacitors is CRRC-03000-C1-2R7; the rated voltage of the super capacitor group is 32.4 V, the total capacity of the super capacitor group is 250 F, the super capacitor group can generate a pulse current of 1-5 kA, and the pulse width ranges between 100-1000 ms; in particular, the connection mode and the number of the super capacitors can be adjusted according to actual test requirements; in particular, in order to ensure that sufficient energy (i.e., pulse current) is applied to the contact resistance, the super capacitor group needs to be in an over-damped state

[0074] The super capacitor group includes a plurality of super capacitors connected in series, the super capacitors have the characteristics of large capacity, high energy density and fast charging and discharging speed, compared with the ordinary capacitors used in the prior art, the super capacitor group can generate a more stable, more accurate and larger-amplitude pulse current, so that the actual high current environment of the high-voltage switch device can be truly reflected, and the accuracy of the contact resistance measurement is improved.

[0075] In the embodiment, the data processing module comprises an ADC / DAC converter and an FPGA data processing chip; a current input end of the ADC / DAC converter is used as a sampling current input end of the data processing module; a voltage input end of the ADC / DAC converter is used as a sampling voltage input end of the data processing module; a data output end of the ADC / DAC converter is electrically connected with a data input end of the FPGA data processing chip; a current control signal output end of the FPGA data processing chip is used as a current control signal output end of the data processing module; a charging control signal output end of the FPGA data processing chip is used as a charging control signal output end of the data processing module; and a voltage amplification control signal output end of the FPGA data processing chip is used as a voltage amplification control signal output end of the data processing module.

[0076] In an optional embodiment, the model of the ADC / DAC converter is AD7066, and the sampling frequency is 10MSPS; the model of the FPGA data processing chip is EP4CE10.

[0077] The combination of the ADC / DAC converter and the FPGA data processing chip can not only control the charging of the super capacitor module by the super capacitor charging module, but also control the generation of the pulse current of the super capacitor module by the pulse current control module, so that more accurate and stable pulse current can be generated, and the collected voltage and current of the contact contact resistance are processed, so that the accurate measurement of the contact contact resistance is realized.

[0078] In the embodiment, the current sampling module is a Hall sensor, the model of which is AHKC-HB, the range of which is 0-5kA, and the accuracy of which is ±0.5%; an input end of the Hall sensor is used as a first current loop end of the current sampling module; an output end of the Hall sensor is used as a first current loop end of the current sampling module; and a sampling current output end of the Hall sensor is used as a sampling current output end of the current sampling module.

[0079] In the embodiment, the switch device contact contact resistance tester further comprises a display module; the display module comprises a touch screen, a data export unit, a test control knob and a state indicating lamp; an input end of the data export unit is electrically connected with a data output end of the FPGA data processing chip; a control instruction output end of the test control knob is electrically connected with a control instruction input end of the FPGA data processing chip; a data input end of the touch screen is electrically connected with a data output end of the FPGA data processing chip; and an input end of the state indicating lamp is electrically connected with a working state output end of the FPGA data processing chip.

[0080] In an optional embodiment, the touch screen is an LCD touch screen, which can have a size of 7 inches or more, and a resolution of 800x480 or higher; the data export unit can be provided with different types of structures, and in this embodiment, a USB interface is provided, which can export the measurement data; the test control knob can also be provided as a button, so as to set the relevant test parameters; and the state indication lamp can indicate the working state of the tester.

[0081] By providing the touch screen, the data export unit, the test control knob and the state indication lamp, the tester can better adapt to the measurement of the contact contact resistance in different scenarios, and can adjust and control the measurement process, thereby improving the accuracy and applicability of the contact contact resistance.

[0082] In this embodiment, the switch device contact contact resistance tester further comprises a tester housing; the super capacitor module, the voltage sampling scaling module, the current sampling module, the super capacitor charging module, the pulse current control module and the data processing module are arranged inside the tester housing; and the display module is arranged on the upper surface of the tester housing.

[0083] In an optional embodiment, the protection level of the tester housing is IP54, the maximum size is not more than 400mm x 300mm x 200mm, and the maximum weight is not more than 10kg.

[0084] By providing the tester housing, the stable and safe operation of the super capacitor module, the voltage sampling scaling module, the current sampling module, the super capacitor charging module, the pulse current control module and the data processing module can be ensured, and the display module on the upper surface of the tester housing can be used to control the test, thereby improving the accuracy and stability of the contact contact resistance measurement.

[0085] In summary, the working principle of the tester provided in the embodiment is specifically as follows: the FPGA data processing chip in the data processing module controls the relay in the super capacitor charging module to be turned on, then the power unit in the super capacitor charging module charges the super capacitor group, the voltage of the super capacitor group is sampled by the capacitor voltage sampling and reduction unit, and the relay is turned off when the voltage of the super capacitor group reaches a set value; then the eighth thyristor in the pulse current control module is controlled to be turned on, so that the loop between the super capacitor module and the contact contact resistance is turned on, the pulse current generated by the super capacitor module can be applied to the contact contact resistance, then the voltage and the capacitance of the contact contact resistance are collected by the contact voltage sampling and amplifying unit and the current sampling module, and then input to the ADC / DAC converter to be converted into a digital signal, and then processed by the FPGA data processing chip, so that the measurement result of the contact contact resistance of the high-voltage switchgear is obtained; wherein the pulse width τ of the pulse current can be adjusted by the on and off time of the switching element in the control circuit; the amplitude I of the pulse current pulse The pulse current can be calculated by the following formula:

[0086]

[0087] Wherein C is the capacitance of the super capacitor group, ΔV is the voltage change of the super capacitor group, and t is the discharge time.

[0088] The pulse current will produce a voltage drop across the contact contact resistance, so the measured contact contact resistance voltage is the resistive voltage drop plus the inductive voltage drop. Please refer to Figure 6 , an equivalent model of the contact contact resistance provided in the embodiment of the utility model; wherein Lc is the inductance of the contact contact resistance, Rc is the contact contact resistance, L1 is the remaining inductance in the current loop except the inductance of the contact contact resistance, L2 is the inductance of the measurement loop, M is the mutual inductance between L1 and L2, and i is the pulse current flowing through the contact contact resistance. Then, after removing the inductive coupling by the decoupling equivalent circuit, the contact contact resistance voltage can be represented as:

[0089]

[0090] Please refer to Figure 7 , a change rate diagram of the pulse current provided in the embodiment of the utility model, after the pulse current reaches the peak value, the current change rate will decrease rapidly, at this time the contact contact resistance current and voltage tend to be in phase, compared with the resistive voltage drop, the inductive voltage drop has little effect on the measurement of the contact contact resistance, that is, under the excitation of the super capacitor, the pulse current generated is similar to the direct current, and then the time-varying curve of the contact contact resistance under the pulse current can be directly obtained according to the following formula:

[0091]

[0092] Where u(t) is the contact resistance voltage, i(t) is the pulse current value, and R(t) is the contact resistance value.

[0093] In one alternative embodiment, please refer to Figure 8 This is a schematic diagram of a pulse current generation circuit for another tester provided in an embodiment of the present invention, as shown below. Figure 8 As shown, the pulse current generating circuit can be equivalent to an RLC circuit, with diodes (i.e., Figure 8 D) is a freewheeling diode, which prevents the supercapacitor from being reverse-charged and prevents circuit oscillation; the maximum voltage of the capacitor charger is 30V and the constant current charging current is 25A. Figure 8 In this diagram, L represents an air-core inductor used to adjust inductance parameters, thereby regulating the waveform of the pulse current; the shunt is a four-terminal coaxial shunt used to measure the loop current waveform; Rc and Lc represent the contact resistance and inductance of the contacts, i.e., the circuit equivalent model of the GIS contacts; the capacitor charger is for supercapacitors (i.e.,... Figure 8 The C in the middle is charged, and then the thyristor (i.e. Figure 8 When the SW in the circuit is turned on, the resulting abnormal pulse current reaches the contact after passing through the conductor impedance and the shunt. The conductor impedance determines the waveform characteristics of the pulse current. During the generation of the pulse current, the current in the circuit exhibits a specific waveform over time, characterized by rapid rise and slow decay. In particular, the required current waveform can be generated according to different detection scenarios by setting the number, width, and interval of pulses. For example, short-width pulses are suitable for rapid detection, while long-width pulses are suitable for in-depth analysis of the contact state.

[0094] In one alternative embodiment, please refer to Figure 9 This is a schematic diagram of another testing instrument provided in an embodiment of the present utility model, as shown below. Figure 9 The system is connected to the mains power supply via a power module. Then, an FPGA chip EP4CE10 controls relays and thyristors to charge and discharge the supercapacitor. Human-machine interaction is then performed via an LCD screen. The measured capacitor voltage, loop current, and GIS contact voltage are converted by an analog-to-digital converter AD7606. The capacitor voltage is reduced by a factor of 10 by a differential amplifier. The loop current is measured by an open-type Hall sensor (model AHKC-HB) and converted to 0–5V. The GIS contact voltage is amplified by a factor of 1–1000 by an instrumentation amplifier AD8253. Finally, the FPGA calculates the time-domain resistance value of the GIS contact. The LCD screen displays the curves of the measured loop current and contact resistance, and the contact status is determined.

[0095] In summary, the utility model discloses the embodiment through the electric connection between super capacitor module, voltage sampling zoom module, current sampling module, super capacitor charging module, pulse current control module and data processing module, the charging of super capacitor module is carried out through super capacitor charging module, thereby make super capacitor module can charge super capacitor, and then control super capacitor through pulse current control module, generate pulse current, make can apply stable big pulse current to contact contact resistance, and the voltage and current of contact contact resistance are sampled through voltage sampling zoom module and current sampling module, then realize the detection of contact contact resistance through data processing module. The utility model discloses through super capacitor module and super capacitor charging module can provide stable pulse current, avoid the pulse current instability and pulse current charge-discharge efficiency low of ordinary capacitor in the prior art, through the connection between voltage sampling zoom module and super capacitor module, the voltage condition of super capacitor module can be monitored, thereby more accurate based on actual test demand adjusts the charging of super capacitor module to super capacitor module, and then ensures that super capacitor module can discharge more accurate stable pulse current, then through voltage sampling zoom module and current sampling module, the current and voltage of contact contact resistance are collected, and the test result of contact contact resistance can be obtained, not only can provide more accurate stable pulse current, but also can avoid the influence of film resistance such as oxidation film, pollution film on the surface of contact on the measurement result, improve the accuracy of contact contact resistance measurement. The tester based on pulse current method of the utility model constructs a set of efficient, accurate detection system through super capacitor energy storage, pulse current generation, real-time data acquisition etc. Not only can satisfy the demand of high-voltage switchgear contact daily maintenance, but also can quickly find potential fault, thereby guarantee the safe operation of equipment, has the remarkable advantage in measurement accuracy, operation convenience and environmental adaptability.

[0096] The above-described specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the utility model, and it should be understood that the above-described only for the specific embodiments of the utility model, and does not limit the protection scope of the utility model. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement etc. within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A contact resistance tester for switchgear contacts, characterized in that, include: The system includes a supercapacitor module, a voltage sampling and scaling module, a current sampling module, a supercapacitor charging module, a pulse current control module, and a data processing module. The contact voltage sampling terminal of the voltage sampling and scaling module is electrically connected to the contact contact resistor; the capacitor voltage sampling terminal of the voltage sampling and scaling module is electrically connected to the voltage sampling terminal of the supercapacitor module; the sampling voltage output terminal of the voltage sampling and scaling module is electrically connected to the sampling voltage input terminal of the data processing module. The first current loop terminal of the current sampling module is electrically connected to the first pulse current loop terminal of the supercapacitor module; the second current loop terminal of the current sampling module is electrically connected to the contact resistor of the contact; the sampling current output terminal of the current sampling module is electrically connected to the sampling current input terminal of the data processing module. The charging voltage output terminal of the supercapacitor charging module is electrically connected to the charging voltage input terminal of the supercapacitor module; the second pulse current loop terminal of the supercapacitor module is electrically connected to the first terminal of the pulse current control module; the second terminal of the pulse current control module is electrically connected to the contact resistor of the contact head. The charging control signal output terminal of the data processing module is electrically connected to the charging control signal input terminal of the supercapacitor charging module; the current control signal output terminal of the data processing module is electrically connected to the current control signal input terminal of the pulse current control module; and the voltage amplification control signal output terminal of the data processing module is electrically connected to the voltage amplification control signal input terminal of the voltage sampling and scaling module.

2. The contact resistance tester for switchgear as described in claim 1, characterized in that, The voltage sampling scaling module includes: a contact voltage sampling amplification unit and a capacitor voltage sampling reduction unit; The voltage sampling terminal of the contact voltage sampling amplification unit serves as the contact voltage sampling terminal of the voltage sampling scaling module, and it is electrically connected to the contact contact resistor. The voltage sampling terminal of the capacitor voltage sampling reduction unit serves as the capacitor voltage sampling terminal of the voltage sampling scaling module, and is electrically connected to the voltage sampling terminal of the supercapacitor module. The voltage amplification control signal input terminal of the contact voltage sampling amplification unit serves as the voltage amplification control signal input terminal of the voltage sampling scaling module; The voltage sampling output terminal of the contact voltage sampling amplification unit and the voltage sampling output terminal of the capacitor voltage sampling reduction unit both serve as the sampling voltage output terminals of the voltage sampling scaling module.

3. The contact resistance tester for switchgear as described in claim 2, characterized in that, The contact voltage sampling and amplification unit specifically includes: a digitally controlled gain instrumentation amplifier, an eleventh resistor, a ninth resistor, a nineteenth resistor, a twentieth resistor, a thirty-ninth resistor, a forty-third resistor, a forty-first resistor, a twenty-first resistor, a thirty-sixth resistor, a fortieth resistor, a forty-second resistor, a forty-fourth resistor, a fourth capacitor, an eleventh capacitor, a twelfth capacitor, a fifth capacitor, a sixth capacitor, a thirteenth capacitor, a fifteenth capacitor, a sixteenth capacitor, a second RF coaxial connector, a sixth diode, a seventh diode, an eighth diode, a tenth diode, a third transistor, and a fourth transistor; The third end of the second RF coaxial connector is electrically connected to the second end of the eleventh resistor; the first end of the eleventh resistor is electrically connected to the second end of the ninth resistor; the first end of the ninth resistor is grounded. The fifth terminal of the second RF coaxial connector is electrically connected to the first terminal of the nineteenth resistor; the second terminal of the nineteenth resistor is electrically connected to the first terminal of the twentieth resistor; the second terminal of the twentieth resistor is grounded. The first terminal of the fourth capacitor is grounded; the second terminal of the fourth capacitor is electrically connected to the second terminal of the ninth resistor; the first terminal of the twelfth capacitor is electrically connected to the first terminal of the twentieth resistor; the second terminal of the twelfth capacitor is grounded; the first terminal of the eleventh capacitor is electrically connected to the second terminal of the fourth capacitor; the second terminal of the eleventh capacitor is electrically connected to the first terminal of the twelfth capacitor. The anode of the sixth diode is electrically connected to the second terminal of the ninth resistor; the cathode of the seventh diode is electrically connected to the second terminal of the ninth resistor; the anode of the eighth diode is electrically connected to the first terminal of the twentieth resistor; and the cathode of the tenth diode is electrically connected to the first terminal of the twentieth resistor. The emitter of the third transistor is electrically connected to the first terminal of the forty-third resistor; the collector of the third transistor is grounded; the base of the third transistor is electrically connected to the second terminal of the thirty-ninth resistor; the first terminal of the forty-first resistor is electrically connected to the base of the third transistor; the second terminal of the forty-first resistor is grounded. The emitter of the fourth transistor is electrically connected to the first terminal of the forty-fourth resistor; the collector of the fourth transistor is grounded; the base of the fourth transistor is electrically connected to the second terminal of the fortyth resistor; the first terminal of the forty-second resistor is electrically connected to the base of the fourth transistor; the second terminal of the forty-second resistor is grounded. The fourth pin of the numerically controlled gain instrumentation amplifier is electrically connected to the emitter of the third transistor; the fifth pin of the numerically controlled gain instrumentation amplifier is electrically connected to the emitter of the fourth transistor; the first pin of the numerically controlled gain instrumentation amplifier is electrically connected to the first terminal of the eleventh resistor; the tenth pin of the numerically controlled gain instrumentation amplifier is electrically connected to the second terminal of the nineteenth resistor; the second pin of the numerically controlled gain instrumentation amplifier is grounded; the ninth pin of the numerically controlled gain instrumentation amplifier is grounded; the third pin of the numerically controlled gain instrumentation amplifier is electrically connected to the first terminal of the fifth capacitor; the second terminal of the fifth capacitor is grounded; and the third pin of the numerically controlled gain instrumentation amplifier is electrically connected to the first terminal of the sixth capacitor. The connection is as follows: the second terminal of the sixth capacitor is grounded; the eighth pin of the numerically controlled gain instrumentation amplifier is electrically connected to the first terminal of the fifteenth capacitor; the second terminal of the fifteenth capacitor is grounded; the eighth pin of the numerically controlled gain instrumentation amplifier is electrically connected to the first terminal of the sixteenth capacitor; the second terminal of the sixteenth capacitor is grounded; the seventh pin of the numerically controlled gain instrumentation amplifier is electrically connected to the first terminal of the twenty-first resistor; the second terminal of the twenty-first resistor is electrically connected to the first terminal of the thirteenth capacitor; the second terminal of the thirteenth capacitor is electrically connected to the second terminal of the thirty-sixth resistor; the first terminal of the thirty-sixth resistor is grounded; the second terminal of the thirteenth capacitor is grounded; the second terminal of the twenty-first resistor is grounded. The negative terminal of the sixth diode serves as the power supply interface for the contact voltage sampling and amplification unit; the positive terminal of the seventh diode serves as the power supply interface for the contact voltage sampling and amplification unit; the negative terminal of the eighth diode serves as the power supply interface for the contact voltage sampling and amplification unit; the positive terminal of the tenth diode serves as the power supply interface for the contact voltage sampling and amplification unit; the second terminal of the forty-third resistor serves as the power supply interface for the contact voltage sampling and amplification unit; the second terminal of the forty-fourth resistor serves as the power supply interface for the contact voltage sampling and amplification unit; the first terminal of the fifth capacitor serves as the power supply interface for the contact voltage sampling and amplification unit; the first terminal of the sixth capacitor serves as the power supply interface for the contact voltage sampling and amplification unit; the first terminal of the fifteenth capacitor serves as the power supply interface for the contact voltage sampling and amplification unit; the first terminal of the sixteenth capacitor serves as the power supply interface for the contact voltage sampling and amplification unit; and the sixth pin of the digitally controlled gain instrumentation amplifier serves as the power supply interface for the contact voltage sampling and amplification unit. The first end of the thirty-ninth resistor serves as the current limiting control port of the contact voltage sampling amplification unit; the first end of the fortieth resistor serves as the current limiting control port of the contact voltage sampling amplification unit. The fourth and fifth pins of the numerically controlled gain instrumentation amplifier are both used as the voltage amplification control signal input terminals of the contact voltage sampling amplification unit. The input terminal of the second RF coaxial connector serves as the voltage sampling terminal of the contact voltage sampling amplification unit; the seventh pin of the digitally controlled gain instrumentation amplifier serves as the voltage sampling output terminal of the contact voltage sampling amplification unit.

4. The contact resistance tester for switchgear as described in claim 2, characterized in that, The capacitor voltage sampling reduction unit specifically includes: a ninth RF coaxial connector, a differential amplifier, a nineteenth capacitor, a fifty-ninth resistor, a thirty-fourth capacitor, a fifty-eighth resistor, and a thirty-fifth capacitor; The second end of the ninth RF coaxial connector is electrically connected to the fifth pin of the differential amplifier; The fifth terminal of the ninth RF coaxial connector is electrically connected to the second pin of the differential amplifier; The second pin of the differential amplifier is electrically connected to the sixth pin of the differential amplifier; The third pin of the differential amplifier is grounded; The fourth pin of the differential amplifier is electrically connected to the first terminal of the nineteenth capacitor; the second terminal of the nineteenth capacitor is grounded. The seventh pin of the differential amplifier is electrically connected to the second terminal of the thirty-fourth capacitor; the first terminal of the thirty-fourth capacitor is grounded. The sixth pin of the differential amplifier is electrically connected to the first terminal of the fifty-eighth resistor; The second end of the fifty-eighth resistor is electrically connected to the first end of the thirty-fifth capacitor; The second terminal of the thirty-fifth capacitor is electrically connected to the second terminal of the fifty-ninth resistor; The first terminal of the fifty-ninth resistor is grounded; the second terminal of the fifty-ninth resistor is grounded; the second terminal of the fifty-eighth resistor is grounded. The seventh pin of the differential amplifier serves as the power supply interface for the capacitor voltage sampling and reduction unit. The fourth pin of the differential amplifier serves as the power supply interface for the capacitor voltage sampling and reduction unit. The input terminal of the ninth RF coaxial connector serves as the voltage sampling terminal of the capacitor voltage sampling reduction unit. The sixth pin of the differential amplifier serves as the voltage sampling output of the capacitor voltage sampling reduction unit.

5. The contact resistance tester for switchgear as described in claim 1, characterized in that, The supercapacitor charging module specifically includes: a sixteenth optocoupler, an eighty-seventh resistor, a ninety-second resistor, a ninety-third resistor, a sixth transistor, a relay, a fourteenth diode, a power supply unit, and a forty-eighth capacitor; The third terminal of the sixteenth optocoupler is electrically connected to the first terminal of the ninety-second optocoupler. The second end of the ninety-second resistor is electrically connected to the base of the sixth transistor; The emitter of the sixth transistor is electrically connected to the positive terminal of the fourteenth diode; The collector of the sixth transistor is grounded; The first end of the ninety-third resistor is electrically connected to the second end of the ninety-second resistor; The second terminal of the ninety-third resistor is grounded; The first end of the sixteenth optocoupler is electrically connected to the first end of the eighty-seventh resistor; The second terminal of the sixteenth optocoupler is grounded; The second terminal of the relay is electrically connected to the positive terminal of the fourteenth diode; The first terminal of the relay is electrically connected to the negative terminal of the fourteenth diode; The fourth terminal of the relay is electrically connected to the first terminal of the power supply unit; The fifth terminal of the relay is electrically connected to the first terminal of the forty-eighth capacitor; The second terminal of the forty-eighth capacitor is electrically connected to the second terminal of the power supply unit. The fourth end of the sixteenth optocoupler serves as the power supply interface for the supercapacitor charging module. The negative terminal of the fourteenth diode serves as the power supply interface for the supercapacitor charging module. The first and second ends of the power supply unit both serve as the charging voltage output terminals of the supercapacitor charging module. The second end of the 87th resistor serves as the charging control signal input terminal for the supercapacitor charging module.

6. The contact resistance tester for switchgear as described in claim 1, characterized in that, The pulse current control module specifically includes: an 86th resistor, a 90th resistor, a 17th optocoupler, a 46th capacitor, a 99th resistor, a 23rd drive control chip, a 100th resistor, a 52nd capacitor, a 97th resistor, a 13th diode, a 20th MOSFET, a 12th diode, a 94th resistor, a 5th transistor, a 91st resistor, an 89th resistor, an 11th diode, a pulse inductor, a 15th diode, a 17th diode, a 49th capacitor, and an 8th thyristor; The first terminal of the eighty-sixth resistor is grounded. The second end of the eighty-sixth resistor is electrically connected to the first end of the ninetieth resistor; The second end of the 90th resistor is electrically connected to the first end of the 17th optocoupler; The second terminal of the seventeenth optocoupler is grounded; The third terminal of the seventeenth optocoupler is grounded; The fourth terminal of the seventeenth optocoupler is electrically connected to the first pin of the twenty-third drive control chip. The fourth terminal of the seventeenth optocoupler is electrically connected to the first terminal of the forty-sixth capacitor; the second terminal of the forty-sixth capacitor is electrically connected to the second pin of the twenty-third drive control chip. The second terminal of the forty-sixth capacitor is electrically connected to the first terminal of the ninety-ninth resistor. The second end of the ninety-ninth resistor is electrically connected to the first end of the one hundredth resistor. The seventh pin of the 23rd drive control chip is electrically connected to the first end of the 100th resistor; The sixth pin of the 23rd drive control chip is electrically connected to the second terminal of the 46th capacitor; The fifth pin of the 23rd drive control chip is electrically connected to the first terminal of the 52nd capacitor; The second terminal of the fifty-second capacitor is electrically connected to the first terminal of the forty-sixth capacitor; The third pin of the 23rd drive control chip is electrically connected to the negative terminal of the 11th diode; the positive terminal of the 11th diode is grounded. The negative terminal of the eleventh diode is electrically connected to the first terminal of the eighty-ninth resistor. The second end of the eighty-ninth resistor is electrically connected to the base of the fifth transistor; The collector of the fifth transistor is grounded; The emitter of the fifth transistor is electrically connected to the second terminal of the ninety-first resistor; The first end of the ninety-fourth resistor is electrically connected to the second end of the ninety-first resistor; The second terminal of the ninety-fourth resistor is grounded; The first terminal of the twelfth diode is electrically connected to the second terminal of the ninety-first resistor; The second terminal of the twelfth diode is grounded; The gate of the twentieth MOS transistor is electrically connected to the second terminal of the ninety-first resistor; The source of the twentieth MOSFET is grounded; The drain of the twentieth MOS transistor is electrically connected to the positive terminal of the thirteenth diode; The negative terminal of the thirteenth diode is electrically connected to the second terminal of the ninety-seventh resistor; The first terminal of the pulse inductor is electrically connected to the second terminal of the ninety-seventh resistor; The second terminal of the pulse inductor is electrically connected to the positive terminal of the thirteenth diode; The third terminal of the pulse inductor is electrically connected to the positive terminal of the fifteenth diode; The fourth terminal of the pulse inductor is electrically connected to the positive terminal of the seventeenth diode; The negative terminal of the fifteenth diode is electrically connected to the negative terminal of the seventeenth diode; The gate of the eighth thyristor is electrically connected to the negative terminal of the fifteenth diode; The cathode of the eighth thyristor is electrically connected to the first terminal of the forty-ninth capacitor. The anode of the eighth thyristor serves as the first terminal of the pulse current control module; The second terminal of the forty-ninth capacitor serves as the second terminal of the pulse current control module. The second terminal of the eighty-sixth resistor serves as the current control signal input terminal of the pulse current control module; The fourth pin of the 23rd drive control chip serves as the power supply interface for the pulse current control module; the eighth pin of the 23rd drive control chip serves as the power supply interface for the pulse current control module; the second end of the 100th resistor serves as the power supply interface for the pulse current control module; the first end of the 91st resistor serves as the power supply interface for the pulse current control module; and the first end of the 97th resistor serves as the power supply interface for the pulse current control module.

7. The contact resistance tester for switchgear as described in claim 1, characterized in that, The supercapacitor module is a supercapacitor bank; the supercapacitor bank includes several supercapacitors connected in series. The positive terminal of the supercapacitor bank serves as the first pulse current loop terminal of the supercapacitor module. The negative terminal of the supercapacitor bank serves as the second pulse current loop terminal of the supercapacitor module. Both the positive and negative terminals of the supercapacitor bank serve as voltage sampling terminals of the supercapacitor module. Both the positive and negative terminals of the supercapacitor bank serve as the charging voltage input terminals of the supercapacitor module.

8. The contact resistance tester for switchgear as described in claim 1, characterized in that, The data processing module includes: an ADC / DAC converter and an FPGA data processing chip; The current input terminal of the ADC / DAC converter serves as the sampling current input terminal of the data processing module; The voltage input terminal of the ADC / DAC converter serves as the sampling voltage input terminal of the data processing module; The data output terminal of the ADC / DAC converter is electrically connected to the data input terminal of the FPGA data processing chip; The current control signal output terminal of the FPGA data processing chip serves as the current control signal output terminal of the data processing module. The charging control signal output terminal of the FPGA data processing chip serves as the charging control signal output terminal of the data processing module. The voltage amplification control signal output terminal of the FPGA data processing chip serves as the voltage amplification control signal output terminal of the data processing module.

9. A contact resistance tester for switchgear as described in claim 8, characterized in that, It also includes a display module; The display module includes: a touch screen, a data export unit, a test control knob, and status indicator lights; The input terminal of the data export unit is electrically connected to the data output terminal of the FPGA data processing chip; The control command output terminal of the test adjustment knob is electrically connected to the control command input terminal of the FPGA data processing chip. The data input terminal of the touch screen is electrically connected to the data output terminal of the FPGA data processing chip; The input terminal of the status indicator light is electrically connected to the working status output terminal of the FPGA data processing chip.

10. A contact resistance tester for switchgear as described in claim 9, characterized in that, It also includes the tester housing; The supercapacitor module, voltage sampling and scaling module, current sampling module, supercapacitor charging module, pulse current control module, and data processing module are located inside the housing of the test instrument. The display module is located on the upper surface of the tester housing.

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