High-voltage large-current dual-application electrical equipment performance test system

Abstract

The utility model relates to the technical field of electrical equipment performance testing, and discloses a high-voltage large-current dual-application electrical equipment performance testing system. The system comprises an artificial star point connecting device, a variable-frequency current applying system, a voltage applying system and a monitoring module based on a PLC (Programmable Logic Controller) and an industrial personal computer, the artificial star point device is connected to the three-phase tail end of the three-phase transformer to form a closed loop; the variable-frequency current system injects adjustable variable-frequency current into the loop through an isolation transformer, a frequency converter and a filter; the voltage system injects adjustable high voltage into one phase through a single-phase transformer, a frequency converter and the like; the industrial personal computer is linked with the PLC and the frequency converter through 485 communication to realize real-time monitoring and remote regulation and control of test voltage and current; the system can be remotely operated, simulates high-voltage and large-current working conditions in real operation of equipment, effectively detects the electrical performance of the equipment, has high reliability, flexibility and safety, and is suitable for performance verification and fault diagnosis of deep sea oil and gas equipment, high-voltage cables and other equipment.

Description

Technical Field

[0001] This utility model relates to the field of electrical equipment performance testing technology, and discloses a high-voltage and high-current dual-application electrical equipment performance testing system. Background Technology

[0002] As offshore oil and gas resource development continues to advance into deeper waters, the reliability and stability of subsea production systems have become key factors affecting oil and gas field operational efficiency and development costs. To ensure the adaptability and long-term stable operation of equipment in complex underwater environments, performance testing and evaluation have become an indispensable part of product research and development and production.

[0003] Currently, the withstand voltage and current carrying capacity tests of electrical equipment are typically conducted separately, with most tests based on DC power supplies. However, this approach has significant limitations: it cannot realistically simulate the combined operating conditions of equipment under both AC voltage and current during actual operation. The combined effect of voltage and current during operation can lead to a decline in the electrical performance of electrical equipment, and existing separate testing methods are insufficient to fully expose such potential defects.

[0004] Furthermore, for high-voltage, high-current equipment (such as equipment with a rated voltage of 5000V and a rated current of 100A), if the rated voltage and current are to be applied simultaneously during testing, the required power is extremely large (e.g., 500kW), and a specific frequency (e.g., 70Hz) must be matched. Traditional testing methods face problems such as high technical difficulty, high equipment cost, and complex operation when achieving the above conditions, making it difficult to promote and apply them in actual testing.

[0005] Therefore, there is an urgent need to develop a testing system capable of simultaneously applying variable frequency AC voltage and current to realistically simulate the electrical environment of electrical equipment during actual operation, thereby more effectively detecting performance defects and improving the reliability and safety of the equipment. This utility model is proposed against this technical background. Utility Model Content

[0006] This invention discloses a high-voltage, high-current dual-application electrical equipment performance testing system. It can simultaneously apply independently adjustable high voltage and high current to the device under test at extremely low power cost, accurately simulating the combined electrical stress conditions of the equipment during actual operation. This invention effectively solves the problems of distortion in the simulation of operating conditions and inability to expose deep defects caused by separate voltage and current testing in existing technologies. It also overcomes the technical bottlenecks of traditional synchronous testing schemes, which are difficult to implement due to the huge power requirements and high costs.

[0007] To achieve the above objectives, this utility model provides a high-voltage, high-current dual-application electrical equipment performance testing system, including the electrical equipment under test and a power supply, characterized in that the electrical equipment performance testing system further includes:

[0008] The artificial star point device includes a conductive connector for short-circuiting the three-phase lines of the electrical equipment under test and a sealed housing that completely encloses the conductive connector. The artificial star point device is connected to the end of the three-phase lines of the frequency conversion current application module and is used to short-circuit the three-phase lines to form a low-impedance loop.

[0009] The variable frequency current application module includes a three-phase frequency converter, a three-phase filter, and a three-phase transformer connected in sequence. The output terminal of the variable frequency current application module is connected to the first end of the three-phase line of the electrical equipment under test, and is used to provide an adjustable test current to the low impedance circuit.

[0010] The voltage application module includes a single-phase frequency converter, a single-phase filter, and a single-phase transformer connected in sequence. The output terminal of the voltage application module is connected between any one phase of the three-phase line of the electrical equipment under test and ground, and is used to establish an adjustable test voltage between the low-impedance circuit and ground.

[0011] Preferably, the sealing housing is constructed as a double-layer structure, with an outer insulating layer and an inner waterproof layer.

[0012] Preferably, the three-phase transformer is an electromagnetic isolation transformer.

[0013] Preferably, the power supply is equipped with a circuit breaker QF4 on the phase line path connected to the electrical device under test.

[0014] Preferably, the three-phase transformer has a star-connected input winding and a delta-connected output winding.

[0015] Preferably, the frequency conversion current application module and the voltage application module are respectively equipped with circuit breakers QF2 and QF3 on the phase line path connected to the electrical equipment under test.

[0016] Preferably, the testing system further includes a control module, and the performance testing system further includes a control module, which includes a higher-level monitoring unit and a lower-level control unit;

[0017] The lower-level control unit is a programmable logic controller (PLC), which is connected to the three-phase frequency converter and the single-phase frequency converter respectively through a communication interface, and is used to directly control the parameters of the test current and the test voltage.

[0018] The upper-level monitoring unit is an industrial control computer, which is communicatively connected to the programmable logic controller (PLC) to provide a human-machine interface and centrally display monitoring data.

[0019] Preferably, the testing system further includes a remote control terminal, which is connected to the upper-level monitoring unit via a wireless local area network to realize remote control and monitoring of the testing process.

[0020] Preferably, the frequency conversion current application module and the voltage application module are integrated and arranged on a skid-mounted base.

[0021] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model include at least the following:

[0022] This system innovatively constructs a low-impedance loop using artificial star points and, based on electromagnetic isolation, frequency conversion control, and filtering technologies, achieves synchronous, independent, and precise application of high voltage and high current to the device under test. It fully replicates the complex electrical stress conditions experienced by electrical equipment in actual operation, completely overcoming the fundamental limitation of traditional testing methods that require the application of high voltage and high current in stages, failing to effectively simulate real working conditions. Compared to traditional solutions that rely on a single ultra-high-power power supply, this invention successfully drives the test with an input power far below the rated power, significantly reducing equipment cost and energy consumption. It is particularly suitable for complex testing scenarios such as non-power frequency, high voltage, and high current. The system integrates a PLC and industrial control computer monitoring system, supports 485 communication and wireless remote control, and can monitor multiple parameters such as voltage, current, and temperature in real time, ensuring the safety and reliability of the testing process. It also achieves physical isolation between operators and the high-voltage site, significantly improving the inherent safety and ease of operation of the test. The system is compact, skid-mountable, highly flexible, reliable, and adaptable. It is suitable for performance verification and fault diagnosis of various electrical equipment such as deep-sea oil and gas equipment and high-voltage cables, and has outstanding engineering application value and economic benefits.

[0023] Other beneficial effects will be discussed in conjunction with specific implementation methods. Attached Figure Description

[0024] This utility model will be described by way of example and with reference to the accompanying drawings, wherein:

[0025] Figure 1 This is a system block diagram of the present invention. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] In the description of this application, it should be noted that the terms used, such as "top" and "bottom," refer to the portion closer to the top and the portion closer to the bottom in the application's usage state; the terms used, such as "first" and "second," are only for distinguishing descriptions and do not indicate or imply a difference in importance or order; the terms used, such as "inner" and "outer," refer to the inner and outer parts of a specific outline. The use of the above terms is only for the purpose of clearly and simply describing the technical solution of this application and should not be construed as limiting this application.

[0028] The applicant found that while there are many existing performance testing schemes for critical electrical equipment such as underwater cables and connectors, most of them still operate by separating withstand voltage testing and current carrying testing, lacking the comprehensive ability to simultaneously reproduce the combined electrical stress of high voltage and high current in a single testing process. Even when some schemes attempt to carry current, they often use DC sources, which is fundamentally different from the actual operating conditions of the equipment under AC power grid conditions. This makes it impossible to effectively expose potential insulation defects and thermal runaway risks caused by the combined effects of alternating electromagnetic fields, eddy current effects, and dielectric losses.

[0029] Some solutions attempt to construct simultaneous application systems, but often fall into the technical trap of "forced coupling," that is, trying to directly drive the device under test with a single power supply possessing enormous apparent power in the KV×KA range. This approach not only results in high cost, bulky size, and staggering energy consumption for the test system, but also presents significant technical and cost hurdles in implementation, especially when simulating non-power frequency (e.g., 70Hz) variable frequency conditions. Customizing such high-power variable frequency power supplies faces almost insurmountable technical and cost barriers, severely compromising their versatility and economic viability. Furthermore, existing high-power testing environments often involve substantial safety risks. Traditional near-field manual operation exposes test personnel directly to potential dangers such as high-voltage arcs and equipment explosions, with severely inadequate safety measures that fail to meet the inherent safety requirements of modern industrial production.

[0030] To solve the above-mentioned technical problems, this utility model provides a high-voltage, high-current dual-application electrical equipment performance testing system, such as... Figure 1 As shown in the figure, the core hardware modules of the electrical equipment performance testing system described in this embodiment include: the electrical equipment under test (shown in the figure as the part connected between the three phases A, B, and C and the artificial star point device), the artificial star point device, the frequency conversion current application module, the voltage application module, and the control module.

[0031] The output terminal of the frequency converter current application module is connected to the first three phase conductors (phases A, B, and C) of the electrical equipment under test. The frequency converter current application module includes a three-phase frequency converter, a three-phase filter, and a three-phase electromagnetic isolation transformer connected in sequence. The ends of the three phase conductors of the frequency converter current application module are connected to an artificial star point device. The artificial star point device includes a conductive connector for short-circuiting the three phase conductors of the electrical equipment under test and a sealed housing that completely encloses the conductive connector. This device electrically short-circuits the three phase conductors, forming a closed, low-impedance current loop.

[0032] The voltage application module has two output terminals, one of which (the high-voltage terminal) is connected to any point in the closed current loop (for example, as shown in the diagram, connected to phase A conductor), while the other terminal (the grounding terminal) is reliably grounded. This connection raises the overall ground potential of the entire current loop to the high voltage required for the test.

[0033] Furthermore, the voltage application module includes a single-phase frequency converter, a single-phase filter, and a single-phase electromagnetic isolation transformer connected in sequence.

[0034] The control module acts as the "brain" of the system. Its lower-level control units (such as PLCs) communicate with the three-phase frequency converters in the variable frequency current application module and the single-phase frequency converters in the voltage application module via an industrial communication bus (such as RS-485) to send control commands and receive status data. The upper-level monitoring unit (such as an industrial computer) communicates with the lower-level control units. In addition, a remote control terminal (not shown in the figure, but part of this system) connects to the upper-level monitoring unit via a wireless local area network to achieve physical isolation from the test site.

[0035] Furthermore, one end of the UPS power supply is connected to the electrical equipment under test, and the other end is connected to the host monitoring industrial control computer.

[0036] It should be noted that the output of the voltage application module can be connected to any of the three phase conductors, not just the A-phase conductor.

[0037] The working principle and process of the electrical equipment performance testing system described in this embodiment are as follows:

[0038] First, the ends of the three-phase electrical equipment under test (phases A, B, and C in the diagram) are short-circuited using an "artificial star point device" to form a low-impedance closed current loop. Next, the "frequency conversion current application module" draws power from the grid, which, after being regulated by a three-phase frequency converter and a three-phase filter, is injected into this closed loop through a three-phase isolation step-down transformer with a star connection for input and a delta connection for output. This injects a precisely controlled low voltage into the loop, thereby exciting the required large current (e.g., 100A), and real-time monitoring and feedback are achieved through a current transformer. Simultaneously, the "voltage application module" independently draws single-phase power from the grid, which, after passing through a single-phase frequency converter, a single-phase filter, and a single-phase step-up transformer, generates the required high voltage (e.g., 5000V). Crucially, this high-voltage output is not directly connected across the loop; instead, the high-voltage live wire is connected to any one phase conductor of the high-current loop (phase A in the diagram), while the other end is directly grounded. Because the current loop is electrically isolated from the source end via a three-phase transformer, this connection raises the overall ground potential of the entire "floating" current loop to the target high voltage value. Ultimately, the device under test (DUT) experiences a large current flow internally while its conductors are subjected to a high voltage test with respect to ground, perfectly simulating actual operating conditions. The entire process is coordinated and controlled by the upper-level monitoring unit and lower-level control unit in the "control module," and the stable operation of the control system is ensured by a UPS power supply, achieving automation, precision, and intrinsic safety in the testing.

[0039] It should be noted that the low-impedance circuit formed by short-circuiting the three-phase conductors through the artificial star point device has extremely low resistance. According to the formula U=IR, when the test current I is constant, the voltage is proportional to the resistance. Therefore, the frequency converter current application module only needs to apply a very small voltage to achieve the rated test current required for the test, and the rated test voltage required for the test can be achieved through a single-phase step-up transformer.

[0040] This proposed solution solves the problem of traditional testing methods, which cannot simultaneously apply high voltage and high current, and cannot realistically simulate equipment operating conditions. By replicating the combined effect of voltage and current, it can more effectively expose potential performance degradation or defects in electrical equipment during actual operation. Secondly, this solution achieves this goal with extremely high efficiency. For example, for a test requiring 5000V and 100A, traditional methods require a huge power supply of nearly 500kW, while this system, through an innovative decoupling and superposition principle, requires only minimal input power, greatly reducing testing costs and implementation difficulty. Furthermore, the integrated PLC, industrial computer, and remote wireless control technology not only enable real-time monitoring of key parameters such as voltage, current, and temperature during the test, but also allow operators to remotely control the system from an absolutely safe distance, completely ensuring personnel safety. In summary, this solution provides a safe, economical, efficient, and highly realistic method for electrical performance testing, which is of great value in improving equipment reliability and stability.

[0041] In some embodiments, the sealing housing is configured as a double-layer structure, with an outer insulating layer and an inner waterproof layer.

[0042] Furthermore, the artificial star point device connects the three-phase conductors together, with any two phase conductors connected to each other. The star point must maintain good insulation performance and conductivity between each phase line to ensure that the overall electrical performance is not affected by the electrical performance of the star point during the test.

[0043] In some embodiments, the transformers are all electromagnetic isolation transformers.

[0044] Furthermore, both the transformers in the frequency conversion current application module and the voltage application module are electromagnetic isolation transformers. In this testing system, the core function of the electromagnetic isolation transformer is to achieve electrical isolation and protection. It transfers energy through magnetic coupling, physically isolating the thousands of volts of high voltage on the downstream device under test from the precision frequency conversion current source equipment (such as the frequency converter) at the front end, effectively preventing high voltage intrusion and damage. At the same time, it works in conjunction with the filter to help output a stable and pure sinusoidal current, and provides a safety reference for the system through its input-side star-point grounding. It is a key component that ensures the entire system can safely and reliably apply high voltage and large current simultaneously, thereby accurately simulating real working conditions.

[0045] In some embodiments, the frequency conversion current application module and the voltage application module are integrated on a skid-mounted base.

[0046] Furthermore, the two application systems are arranged together using a skid-mounted design, and their mutual interference is prevented through proper layout and electrical isolation. The inverter control panels within each application system are then unified onto a single operation panel for convenient operation and testing.

[0047] In some embodiments, circuit breakers QF2 and QF3 are respectively installed on the phase line path of the frequency conversion current application module and the voltage application module connected to the electrical equipment under test, so as to realize the power supply switching, overload and short circuit protection of the frequency conversion current application module and the voltage application module.

[0048] The circuit breakers are primarily used to achieve two main functions: manual power isolation and automatic fault protection. Firstly, during equipment maintenance, debugging, or emergencies, QF2 or QF3 can be manually disconnected to provide reliable electrical isolation to the corresponding downstream application module, ensuring operational safety. Secondly, when a short circuit or overload fault occurs within any module (such as the frequency converter, transformer, or connecting lines), the corresponding circuit breaker will automatically trip, quickly cutting off the power supply and protecting the core power electronic equipment from damage. Furthermore, both QF2 and QF3 are equipped with auxiliary contacts, whose on / off status signals are transmitted to the PLC in the control module. The control system uses this signal to monitor the power status of the two application systems in real time and can use this signal as a critical safety interlock condition. For example, once a circuit breaker trip is detected, the frequency converter operation is immediately stopped or the system startup is prohibited, thus constructing a multi-layered safety protection system.

[0049] Furthermore, a circuit breaker QF4 is also installed on the power supply path to the phase line of the electrical device under test. At the same time, a circuit breaker QF1 is installed at the beginning of the phase line to provide dedicated and direct overcurrent and short-circuit protection for the device under test (EUT) and its connected lines, and to serve as the emergency disconnection and overall isolation point at the front end of the test circuit.

[0050] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model.

Claims

1. A high-voltage, high-current dual-application electrical equipment performance testing system, comprising the electrical equipment under test and a power supply, characterized in that, Also includes: The artificial star point device includes a conductive connector for short-circuiting the three-phase lines of the electrical equipment under test and a sealed housing that completely encloses the conductive connector. The artificial star point device is connected to the end of the three-phase lines of the frequency conversion current application module and is used to short-circuit the three-phase lines to form a low-impedance loop. The variable frequency current application module includes a three-phase frequency converter, a three-phase filter, and a three-phase transformer connected in sequence. The output terminal of the variable frequency current application module is connected to the first end of the three-phase line of the electrical equipment under test, and is used to provide an adjustable test current to the low impedance circuit. The voltage application module includes a single-phase frequency converter, a single-phase filter, and a single-phase transformer connected in sequence. The output terminal of the voltage application module is connected between any one phase of the three-phase line of the electrical equipment under test and ground, and is used to establish an adjustable test voltage between the low-impedance circuit and ground.

2. The high-voltage, high-current dual-application electrical equipment performance testing system according to claim 1, characterized in that, The sealed housing is constructed as a double-layer structure, with an outer insulating layer and an inner waterproof layer.

3. The high-voltage, high-current dual-application electrical equipment performance testing system according to claim 1, characterized in that, The three-phase transformer is an electromagnetic isolation transformer.

4. The high-voltage, high-current dual-application electrical equipment performance testing system according to claim 1, characterized in that, The power supply is equipped with a circuit breaker QF4 on the phase line path connected to the electrical equipment under test.

5. The high-voltage, high-current dual-application electrical equipment performance testing system according to claim 1, characterized in that, The single-phase transformer is an electromagnetic isolation transformer.

6. The high-voltage, high-current dual-application electrical equipment performance testing system according to claim 1, characterized in that, The three-phase transformer has a star-connected input winding and a delta-connected output winding.

7. The high-voltage, high-current dual-application electrical equipment performance testing system according to claim 1, characterized in that, The variable frequency current application module and the voltage application module are respectively equipped with circuit breakers QF2 and QF3 on the phase line path connected to the electrical equipment under test.

8. The high-voltage, high-current dual-application electrical equipment performance testing system according to claim 1, characterized in that, The performance testing system also includes a control module, which includes a higher-level monitoring unit and a lower-level control unit. The lower-level control unit is a programmable logic controller (PLC), which is connected to the three-phase frequency converter and the single-phase frequency converter respectively through a communication interface, and is used to directly control the parameters of the test current and the test voltage. The upper-level monitoring unit is an industrial control computer, which is communicatively connected to the programmable logic controller (PLC) to provide a human-machine interface and centrally display monitoring data.

9. The high-voltage, high-current dual-application electrical equipment performance testing system according to claim 8, characterized in that, The testing system also includes a remote control terminal, which is connected to the upper-level monitoring unit via a wireless local area network to enable remote control and monitoring of the testing process.

10. The high-voltage, high-current dual-application electrical equipment performance testing system according to claim 1, characterized in that, The frequency conversion current application module and the voltage application module are integrated and arranged on a skid-mounted base.

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