A load testing system

Abstract

The utility model discloses a kind of load test systems, for the aging test of frequency converter, it includes load motor and energy feedback device;The load motor is connected to power grid by frequency converter to be tested;The energy feedback device includes inverter module and synchronous detection module;The direct current output terminal of the frequency converter is electrically connected with the direct current input terminal of the inverter module;The alternating current output terminal of the inverter module is electrically connected with the power grid;When the load motor decelerates, the direct current that the inverter module can obtain, and direct current is converted into alternating current with the same frequency as power grid;The synchronous detection module is signal connected with the inverter module, for adjusting the output phase of the inverter module, to make the electrical energy converted by the inverter module feedback to power grid.The utility model technical scheme aims at reducing energy consumption in the aging test process of frequency converter, reduce electricity cost.

Description

Technical Field

[0001] This utility model relates to the field of frequency converter testing technology, and in particular to a load testing system. Background Technology

[0002] As power electronic devices, frequency converters are widely used in industrial motor control, new energy power generation, electric vehicles, and other fields. To ensure their long-term operational stability and reliability, they typically undergo aging tests before leaving the factory. This involves continuous operation under rated or over-rated conditions to simulate long-term usage environments and screen for potential defects. Traditional load testing systems usually use resistive loads or motor loads to simulate actual operating conditions by consuming electrical energy. However, this method suffers from significant energy waste, high heat dissipation requirements, and high testing costs. Utility Model Content

[0003] The purpose of this invention is to provide a load testing system that aims to solve the problems of high energy consumption and high electricity costs during the aging test of frequency converters.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] A load testing system for aging tests of frequency converters includes a load motor and an energy feedback device; the load motor is connected to the power grid via the frequency converter under test; the energy feedback device includes an inverter module and a synchronization detection module.

[0006] The DC output terminal of the frequency converter is electrically connected to the DC input terminal of the inverter module; the AC output terminal of the inverter module is electrically connected to the power grid; when the load motor decelerates, the inverter module can obtain DC power and convert it into AC power with the same frequency as the power grid; the synchronization detection module is signal-connected to the inverter module and is used to adjust the output phase of the inverter module so that the electrical energy converted by the inverter module is fed back to the power grid.

[0007] In one embodiment, the energy feedback device further includes a filter circuit for filtering out high-frequency harmonics emitted by the inverter module.

[0008] In one embodiment, the energy feedback device further includes a voltage monitoring module and a logic control module. The voltage monitoring module is used to monitor the DC voltage output by the frequency converter in real time. The logic control module is signal-connected to the voltage monitoring module and is used to control the start-up of the inverter module. The synchronization detection module is signal-connected to the inverter module through the logic control module and is used to control the output phase of the inverter module to synchronize with the power grid.

[0009] In one embodiment, the load testing system is used for aging tests of multiple sets of frequency converters. When multiple sets of frequency converters control the deceleration of the load motor, the energy feedback device can recover energy during the deceleration process of the multiple sets of load motors.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] This utility model's load testing system effectively solves the technical problems of high energy consumption and high electricity costs during inverter aging tests by incorporating an energy feedback device. Specifically, the testing system mainly consists of a load motor and an energy feedback device, which includes an inverter module and a synchronization detection module. Under the control of the inverter, during the deceleration process of the load motor, the load motor operates as a generator, converting mechanical energy into electrical energy and feeding it back to the inverter's DC bus. At this time, the inverter module converts the regenerated electrical energy generated at the inverter's DC output into AC power synchronized with the power grid, and the synchronization detection module adjusts the output phase in real time to ensure stable energy feedback to the grid. This allows the energy fed back to the grid to be used for other local loads, reducing energy consumption and lowering local electricity costs. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0014] Figure 1 This is a schematic diagram of the circuit connection of the load testing system of this utility model;

[0015] Figure 2 This is a schematic diagram of the system structure of the load testing system of this utility model;

[0016] Figure 3 This is a schematic diagram illustrating the logic principle of the energy recovery device of this utility model;

[0017] Illustration: 100, Load testing system; 110, Load motor; 120, Energy feedback device; 121, Inverter module; 122, Synchronization detection module; 123, Filter circuit; 124, Voltage monitoring module; 125, Logic control module; 130, Power grid. Detailed Implementation

[0018] To make the technical objectives, features, and advantages of this utility model more apparent and understandable, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0019] In the description of this utility model, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component centrally located at the same time.

[0020] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0021] This utility model embodiment provides a load testing system 100.

[0022] In some testing techniques, inverter aging tests typically require simulating actual operating conditions with a motor load and controlling the inverter's acceleration and deceleration to verify its performance. However, during deceleration, the load motor 110 operates as a generator, converting mechanical energy into electrical energy and feeding it back to the inverter's DC bus. This causes the DC bus voltage to rise, potentially triggering the inverter's overvoltage protection and affecting the continuity of the test. Furthermore, this energy is not effectively fed back to the grid 130, resulting in energy waste.

[0023] Please see Figures 1 to 3In one embodiment of the present invention, the load testing system 100 is used for aging testing of frequency converters, and includes a load motor 110 and an energy feedback device 120; the load motor 110 is connected to the power grid 130 through the frequency converter under test; the energy feedback device 120 includes an inverter module 121 and a synchronous detection module 122.

[0024] The DC output terminal of the frequency converter is electrically connected to the DC input terminal of the inverter module 121; the AC output terminal of the inverter module 121 is electrically connected to the power grid 130; when the load motor 110 decelerates, the inverter module 121 can obtain DC power and convert it into AC power with the same frequency as the power grid 130; the synchronization detection module 122 is signal-connected to the inverter module 121 and is used to adjust the output phase of the inverter module 121 so that the electrical energy converted by the inverter module 121 is fed back to the power grid 130.

[0025] Specifically, in the load testing system 100, the load motor 110 serves as a test load to simulate the actual operating conditions of the frequency converter. The load motor 110 can be an AC asynchronous motor or a permanent magnet synchronous motor.

[0026] The energy feedback device 120 consists of an inverter module 121 and a synchronous detection module 122, and is used to recover regenerated electrical energy when the load motor 110 decelerates. The inverter module 121 is used to convert DC power into AC power with the same frequency as the power grid 130, and the setting of the inverter module 121 can avoid triggering the overvoltage protection of the frequency converter, thereby improving the continuity of the testing process.

[0027] Furthermore, the synchronization detection module 122 is used to adjust the output phase of the inverter module 121 to synchronize it with the power grid 130, and to safely and efficiently feed back to the power grid 130.

[0028] It is understood that the load testing system 100 described in this embodiment effectively solves the technical problems of high energy consumption and high electricity costs during the inverter aging test by setting up the energy feedback device 120. Specifically, the testing system mainly consists of a load motor 110 and an energy feedback device 120, wherein the energy feedback device 120 includes an inverter module 121 and a synchronization detection module 122. Under the control of the inverter, during the deceleration process of the load motor 110, the load motor 110 operates as a generator, converting mechanical energy into electrical energy and feeding electrical energy back to the DC bus of the inverter; at this time, the inverter module 121 converts the regenerative electrical energy generated at the DC output of the inverter into AC power synchronized with the grid 130, and adjusts the output phase in real time through the synchronization detection module 122 to ensure that the electrical energy is stably fed back to the grid 130, so that the electrical energy fed back to the grid 130 can be used for other local loads, reducing energy consumption and lowering local electricity costs.

[0029] Please continue reading. Figure 1 and Figure 2 In one specific embodiment, the energy feedback device 120 further includes a filter circuit 123, which is used to filter out high-frequency harmonics emitted by the inverter module 121. Specifically, the filter circuit 123 is connected between the AC output terminal of the inverter module 121 and the power grid 130, and is used to filter the AC power output by the inverter module 121 to reduce the interference of high-frequency switching noise on the power grid 130.

[0030] Furthermore, the energy feedback device 120 also includes a voltage monitoring module 124 and a logic control module 125. The voltage monitoring module 124 is used to monitor the DC voltage output by the frequency converter in real time. The logic control module 125 is signal-connected to the voltage monitoring module 124 and is used to control the start-up of the inverter module 121. The synchronization detection module 122 is signal-connected to the inverter module 121 through the logic control module 125 and is used to control the output phase of the inverter module 121 to be synchronized with the power grid 130.

[0031] Specifically, the voltage monitoring module 124 is used to measure the voltage value at the DC bus terminal of the frequency converter, providing key parameters for the start-stop control and energy feedback of the inverter module 121. It should be noted that fluctuations in the DC bus voltage at the inverter module 121 directly affect the modulation ratio and feedback efficiency of the inverter module 121, requiring real-time monitoring.

[0032] Specifically, the logic control module 125 controls the start and stop of the inverter module 121 based on data from the voltage monitoring module 124, ensuring the safety and efficiency of energy feedback. It should be explained that overvoltage at the DC bus terminal may damage the inverter module 121; undervoltage will cause feedback interruption. Therefore, threshold protection is required. When the voltage detected by the voltage monitoring module 124 is within the control range of the logic control module 125, and under the phase adjustment of the power grid 130 detected by the synchronization detection module 122, the inverter module 121 is started to ensure that the regenerated AC power is in phase and frequency with the electrical energy in the power grid 130. Optionally, the logic control module 125 is a PCL controller or an MCU control unit.

[0033] In one embodiment, the load testing system 100 is used for aging tests of multiple sets of frequency converters. When multiple sets of frequency converters control the load motor 110 to decelerate, the energy feedback device 120 can complete the energy recovery during the deceleration process of the multiple sets of load motors 110.

[0034] It is understandable that the energy recovery device can recover energy during the deceleration process of multiple load motors 110, achieving efficient energy recovery in large-scale inverter aging test scenarios.

[0035] It should also be understood that in any of the above embodiments, the load motor 110 operates under load. Preferably, the load of the load motor 110 is a counter-drive motor.

[0036] In summary, the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A load testing system for aging tests of frequency converters, characterized in that, It includes a load motor and an energy feedback device; the load motor is connected to the power grid via the frequency converter under test; the energy feedback device includes an inverter module and a synchronization detection module; The DC output terminal of the frequency converter is electrically connected to the DC input terminal of the inverter module; the AC output terminal of the inverter module is electrically connected to the power grid; when the load motor decelerates, the inverter module can obtain DC power and convert it into AC power with the same frequency as the power grid; the synchronization detection module is signal-connected to the inverter module and is used to adjust the output phase of the inverter module so that the electrical energy converted by the inverter module is fed back to the power grid.

2. The load testing system as described in claim 1, characterized in that, The energy feedback device further includes a voltage monitoring module and a logic control module. The voltage monitoring module is used to monitor the DC voltage output by the frequency converter in real time. The logic control module is signal-connected to the voltage monitoring module and is used to control the start-up of the inverter module. The synchronization detection module is signal-connected to the inverter module through the logic control module and is used to control the output phase of the inverter module to synchronize with the power grid.

3. The load testing system as described in claim 2, characterized in that, The energy feedback device also includes a filter circuit, which is used to filter out high-frequency harmonics emitted by the inverter module.

4. The load testing system as described in any one of claims 1-3, characterized in that, The load testing system is used for aging tests of multiple sets of frequency converters. When multiple sets of frequency converters control the deceleration of the load motor, the energy feedback device can recover energy during the deceleration process of multiple sets of load motors.

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