High-precision high-voltage motor insulation impedance measuring device

Abstract

The invention discloses a high-precision high-voltage motor insulation resistance measuring device, which comprises a shell, and is characterized by comprising a dual-power supply module, a super capacitor management module, an ultra-low noise multi-path output DC / DC module and a high-voltage power supply protection mechanism, the dual-power supply module comprises an AC power supply and a super capacitor; the super capacitor management module comprises a BUCK super capacitor charging circuit, a BOOST super capacitor charging circuit and a super capacitor voltage-sharing and overvoltage protection circuit; the ultra-low noise multi-path output DC / DC module comprises a soft switch DC / DC and a semiconductor switch device; the high-voltage power supply protection mechanism comprises a voltage loop, a current loop and a double-source control output voltage; the dual-power supply module, the super capacitor management module, the ultra-low noise multi-path output DC / DC module and the high-voltage power supply protection mechanism are electrically connected and installed in the shell.

Description

Technical Field

[0001] The invention relates to a high-voltage motor insulation impedance detection technology, in particular to a high-precision high-voltage motor insulation impedance measurement device. Background Art

[0002] High-voltage motors are a common type of electric mechanical equipment in modern industry. Their function is to convert electrical energy into mechanical energy to drive various mechanical equipment. The normal operation of the motor is crucial to the stability and production efficiency of the production line. However, the insulation system of the high-voltage motor may be damaged due to a variety of reasons, such as humidity, temperature, high or low voltage, etc. In order to ensure the normal operation of the high-voltage motor, it is very important to regularly measure the insulation and perform high-voltage motor insulation testing. The insulation material in the motor is used to prevent current leakage or short circuits to ensure the safe operation of the equipment. Over time, due to factors such as aging, thermal stress, mechanical stress, etc., the insulation performance may deteriorate, which will affect the working efficiency of the motor and even cause failure.

[0003] High-voltage motor insulation testing is one of the important measures to ensure the normal operation of high-voltage motors. By regularly measuring insulation and conducting motor insulation testing, and repairing and replacing insulation materials, motor failures and accidents can be avoided, and the reliability and service life of high-voltage motors can be improved.

[0004] At present, the detection of high-voltage motor insulation impedance is mainly carried out manually. Manual measurement has great risks and can easily cause safety accidents. In addition, the manual measurement process is complicated, the detection time is long, the efficiency is low, the detection accuracy is low, the detection data is not easy to store, and the detection data cannot be analyzed scientifically and effectively. With the continuous development of the power system, the reliability and stability requirements of high-voltage motors are getting higher and higher. Therefore, a new measurement device that can improve measurement accuracy and reduce the influence of external interference is needed to meet the needs of modern power systems.

[0005] Therefore, it is necessary to provide a high-precision high-voltage motor insulation resistance measuring device to solve the above technical problems. Summary of the invention

[0006] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0007] To solve the above technical problems, the present invention provides the following technical solutions: a high-precision high-voltage motor insulation impedance measuring device, comprising a shell, characterized in that: it includes a dual power supply module, a supercapacitor management module, an ultra-low noise multi-channel output DC / DC module and a high-voltage power supply protection mechanism; the dual power supply module includes AC power supply and supercapacitor; the supercapacitor management module includes a BUCK supercapacitor charging circuit, a BOOST supercapacitor charging circuit and a supercapacitor voltage balancing and overvoltage protection circuit; the ultra-low noise multi-channel output DC / DC module includes a soft switching DC / DC and a semiconductor switching device; the high-voltage power supply protection mechanism includes a voltage loop, a current loop and a dual-source control output voltage; the dual power supply module, the supercapacitor management module, the ultra-low noise multi-channel output DC / DC module and the high-voltage power supply protection mechanism are electrically connected and arranged inside the individual.

[0008] As a preferred solution of the high-precision high-voltage motor insulation impedance measuring device of the present invention, the dual power supply module includes AV220V and a super capacitor. When in standby mode, the system is powered by AC220V, and when measuring, it is powered by a super capacitor.

[0009] As a preferred solution of the high-precision high-voltage motor insulation impedance measuring device of the present invention, the dual power supply module also includes a bidirectional voltage converter, and the AC power supply, the bidirectional voltage transformer and the super capacitor are electrically connected.

[0010] As a preferred solution of the high-precision high-voltage motor insulation impedance measurement device of the present invention, the ultra-low noise multi-output DC / DC module adopts soft switching DC-DC to reduce the noise and ripple of each output voltage; the circuit operates in resonant mode, and the semiconductor switching device operates in ZVS state.

[0011] As a preferred solution of the high-precision high-voltage motor insulation impedance measuring device of the present invention, the voltage loop has additional undervoltage protection to prevent short-circuit instantaneous current from breaking through the current loop device.

[0012] As a preferred solution of the high-precision high-voltage motor insulation impedance measurement device of the present invention, the device also includes a single-chip microcomputer, a relay and an extremely wide resistance measurement range. The input power supply is disconnected through internal control. During this measurement process, the supercapacitor performs voltage boosting and power supply internally through the single-chip microcomputer to issue instructions, cut off the relay, and disconnect the external power supply. At the same time, the single-chip microcomputer issues instructions to close the supercapacitor power supply relay to realize the supercapacitor power supply circuit of the entire system. The extremely wide resistance measurement range includes a high-resistance input operational amplifier and a wide range of measurement resistance. The circuit is divided into 3 levels for switching, corresponding to resistance measurement values ​​in different ranges, and a variable output voltage, and the output voltage can change with the load.

[0013] The beneficial effects of the present invention are as follows: the input source of the high-voltage output uses supercapacitor power supply during the test process, which can avoid the noise and interference introduced by the power supply part and improve the measurement accuracy. At the same time, the input power supply is disconnected through internal control, and the measurement process is all boosted and powered by the supercapacitor. The single-chip microcomputer issues instructions to cut off the relay and disconnect the external power supply. At the same time, the single-chip microcomputer issues instructions to close the supercapacitor power supply relay to realize the supercapacitor power supply circuit of the entire system. At the same time, it also has a high-voltage power supply protection mechanism, and the voltage loop has additional undervoltage protection to prevent short-circuit instantaneous current from breaking through the current loop device. The present application can also realize remote communication control for automatic measurement, and form a chart of the measurement data, and make certain predictions and preventions on the future trend of the insulation impedance of the high-voltage motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0015] in:

[0016] Figure 1 A schematic diagram of the structure of a dual power supply module of a high-precision high-voltage motor insulation impedance measurement device disclosed in an embodiment of the present invention;

[0017] Figure 2 A schematic diagram of the structure of a low-noise multi-channel output DC / DC module of a high-precision high-voltage motor insulation impedance measurement device disclosed in an embodiment of the present invention;

[0018] Figure 3 A schematic diagram of the connection of a supercapacitor management module of a high-precision high-voltage motor insulation impedance measurement device disclosed in an embodiment of the present invention;

[0019] Figure 4 A schematic diagram of three connection measures for the resistance measurement range of a high-precision high-voltage motor insulation impedance measurement device disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, but not all of the embodiments.

[0021] Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without making any creative work should fall within the scope of protection of the present invention.

[0022] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0023] Example 1

[0024] Reference Figure 1-4A high-precision high-voltage motor insulation impedance measurement device includes a housing, characterized in that it includes a dual power supply module, a supercapacitor management module, an ultra-low noise multi-channel output DC / DC module and a high-voltage power supply protection mechanism; the dual power supply module includes AC power supply and supercapacitor; when on standby, the system uses AC220V power supply, and uses supercapacitor power supply during measurement. The supercapacitor management module includes a BUCK supercapacitor charging circuit, a BOOST supercapacitor charging circuit and a supercapacitor voltage balancing and overvoltage protection circuit; the ultra-low noise multi-channel output DC / DC module includes a soft switch DC / DC and a semiconductor switch device; the high-voltage power supply protection mechanism includes a voltage loop, a current loop and a dual-source control output voltage; the dual power supply module, the supercapacitor management module, the ultra-low noise multi-channel output DC / DC module and the high-voltage power supply protection mechanism are electrically connected and set in the case inside the individual. Specifically, in order to improve the signal-to-noise ratio of the equipment and expand the measurement range, the dual power supply module selects AC power supply and supercapacitor, a dual power supply mode. When on standby, the system uses AC220V power supply, and uses supercapacitor power supply during measurement. The advantages of using dual modules for power supply are: low noise, when measuring, turn off the AC-DC power supply; supercapacitor has a long life and can work stably for more than 10 years, avoiding the life problem of lithium batteries. When using supercapacitors for power supply, grounding is used to avoid leakage interference with measurement errors. Ultra-low noise multi-channel output DC / DC module uses soft switching DC-DC to greatly reduce the noise and ripple of each output voltage. The circuit works in resonant mode and the semiconductor switching device works in ZVS state. Resonant modes include series resonance and parallel resonance. Series resonance means that in a series LC circuit, when the frequency of the input signal is equal to the natural resonant frequency of the circuit, the circuit presents the lowest impedance (generally zero). At this time, only the resistor works in the circuit. In this state, the voltage on the inductor and the voltage on the capacitor are equal and opposite in direction, and the energy generated between them is converted back and forth between the two. Parallel resonance means that in a parallel LC circuit, when the frequency reaches the resonance point, the circuit presents the highest impedance. Under parallel resonance conditions, the circuit presents a high impedance state to external signals, which can be used to selectively prevent certain frequencies from passing. In series resonance, the circuit presents minimum impedance to the signal at the resonant frequency, which is conducive to signal transmission. In parallel resonance, the circuit presents maximum impedance to the signal at the resonant frequency, which can be used to isolate or select signals. In resonant mode, the circuit's selectivity is enhanced, that is, there is a higher gain for signals close to the resonant frequency, while signals far from the resonant frequency are attenuated. The supercapacitor management module consists of three circuits: the BUCK supercapacitor charging circuit, the BOOST supercapacitor discharging circuit, and the supercapacitor voltage equalization and overvoltage protection circuit.The BUCK supercapacitor circuit is based on the working principle of the buck converter (BUCK converter), which can convert the input voltage into a lower stable output voltage, thereby efficiently and stably charging the supercapacitor. When the switch tube is turned on, the power supply supplies power to the load through the inductor, and the inductor stores energy at the same time; when the switch tube is turned off, the magnetic field in the inductor is converted into electrical energy and continues to supply power to the load, and the supercapacitor begins to charge at this time; controlling the frequency and duty cycle of the switch can adjust the output voltage so that the supercapacitor obtains the required charging voltage. The BOOST supercapacitor discharge circuit is able to maintain a constant output voltage when the supercapacitor voltage drops, and is suitable for application scenarios that require a stable voltage supply. The BOOST converter is a DC-DC converter whose main feature is that it can operate when the input voltage is lower than the output voltage. The core components of the BOOST circuit include a switching element (usually MOSFET), an energy storage inductor, a diode (used to prevent current backflow), and an output filter capacitor. The working principle of the BOOST supercapacitor discharge circuit includes: (1) Switch on stage: When the switch element is turned on, the supercapacitor supplies power to the load through the inductor, and the inductor stores energy. At this time, the current in the inductor gradually increases. (2) Switch off stage: When the switch element is disconnected, the current in the inductor cannot be interrupted immediately, so the inductor will generate a voltage in the opposite direction of the original current, forcing the current to continue to flow through the load and the diode. This process transfers the energy in the inductor to the load, and because the voltage generated by the inductor is higher than the voltage of the supercapacitor, the voltage obtained by the load will be higher than the input voltage. (3) Output voltage regulation: By adjusting the on time and off time of the switch element (that is, the duty cycle of the PWM pulse width modulation signal), the output voltage can be controlled to keep it at a stable level. The supercapacitor voltage equalization and overvoltage protection circuit is a supercapacitor voltage equalization circuit that balances the voltage distribution between multiple supercapacitors connected in series to ensure that each capacitor is subjected to the same voltage. The supercapacitor overvoltage protection circuit is to prevent the supercapacitor from being subjected to pressure exceeding its rated voltage. Once this happens, the capacitor may be damaged or even exploded.

[0025] At the same time, it also has a high-voltage power supply protection mechanism circuit. When the output voltage is very high (>1000V), a large current will be generated at the moment of output short circuit, which is easy to burn out the components in the circuit. This circuit has the following characteristics: (1) The voltage loop, current loop and dual loop control the output voltage. While stabilizing the output voltage, the maximum output current can be limited. Even if the output is short-circuited, it can still work at a constant current. (2) The current loop has additional undervoltage protection to prevent the short-circuit instantaneous current from breaking through the current loop components. (3) The high-voltage output end is connected in series with a current-limiting resistor, and the resistance value is automatically corrected in the program. The input source of the high-voltage output uses supercapacitor power supply during the test process, which can avoid the noise and interference introduced by the power supply part and improve the measurement accuracy; at this time, the input power supply is disconnected through internal control, and the measurement process is all boosted and powered by the supercapacitor.

[0026] If an extremely wide resistance measurement range is encountered, the present invention adopts the following three measures: (1) a high-resistance input operational amplifier; (2) when measuring resistance in a wide range, the circuit is divided into three levels for switching, and the resistance measurement values ​​corresponding to different ranges are set; (3) a variable output voltage is set, and the output voltage can change with the load.

[0027] In summary, the accuracy of the high-voltage motor insulation impedance measurement device can be improved through the cooperation between the modules. The input source of the high-voltage output uses an ultra-capacitor power supply during the test process, which can avoid the noise and interference introduced by the power supply part and improve the measurement accuracy. This application has industrial RS485, Ethernet and LoRa communication functions, and can start the high-voltage motor insulation impedance measurement regularly or irregularly through remote control, and save and analyze the test data to form a chart.

[0028] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0029] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0030] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A high-precision high-voltage motor insulation impedance measuring device, comprising a housing, characterized in that: It includes a dual power supply module, a super capacitor management module, an ultra-low noise multi-channel output DC / DC module and a high-voltage power supply protection mechanism; the dual power supply module includes AC power supply and super capacitor; the super capacitor management module includes BUCK super capacitor charging circuit, BOOST super capacitor charging circuit and super capacitor voltage balancing and overvoltage protection circuit; the ultra-low noise multi-channel output DC / DC module includes a soft switching DC / DC and a semiconductor switching device; the high-voltage power supply protection mechanism includes a voltage loop, a current loop and a dual-source control output voltage; the dual power supply module, the super capacitor management module, the ultra-low noise multi-channel output DC / DC module and the high-voltage power supply protection mechanism are electrically connected and installed inside the shell.

2. The high-precision high-voltage motor insulation impedance measuring device according to claim 1 is characterized in that: The dual power supply module includes AV220V and a super capacitor. When in standby mode, the system is powered by AC220V, and when measuring, it is powered by a super capacitor.

3. The high-precision high-voltage motor insulation impedance measuring device according to claim 1 is characterized in that: The dual power supply module also includes a bidirectional voltage converter, and the AC power supply, the bidirectional voltage transformer and the super capacitor are electrically connected.

4. The high-precision high-voltage motor insulation impedance measuring device according to claim 1 is characterized in that: The ultra-low noise multi-channel output DC / DC module adopts soft switching DC-DC to reduce the noise and ripple of each output voltage; the circuit works in the resonance mode, and the semiconductor switch device works in the ZVS state.

5. The high-precision high-voltage motor insulation impedance measuring device according to claim 1 is characterized in that: The voltage loop has additional undervoltage protection to prevent short-circuit instantaneous current from breaking through the current loop components.

6. The high-precision high-voltage motor insulation impedance measuring device according to claim 1 is characterized in that: The device also includes a single-chip microcomputer, a relay and an extremely wide resistance measurement range. The input power supply is disconnected through internal control. The measurement process is all carried out by the supercapacitor for boosting and power supply. The single-chip microcomputer issues instructions to cut off the relay and disconnect the external power supply. At the same time, the single-chip microcomputer issues instructions to close the relay of the supercapacitor power supply to realize the supercapacitor power supply circuit of the entire system. The extremely wide resistance measurement range includes a high-resistance input operational amplifier and a wide range of resistance measurement. The circuit is divided into 3 gears for switching. The output voltage can be changed corresponding to the resistance measurement value in different ranges, and the output voltage can change with the load.

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