System for testing low-voltage ride-through capability of frequency converter

Abstract

A frequency converter low voltage ride through capability test system comprises a test module, a control module, a protection module, a warning module and a terminal. The test module comprises a three-phase rectification unit, a three-phase controllable inversion unit, a digital storage oscillograph and an analog load unit. The control module comprises a processing unit, a voltage control unit, a digital storage oscillograph signal receiving unit and a warning module control unit; and the terminal can receive the information transmitted by the control module and perform data storage through the data storage unit. According to the invention, changes of various electrical quantities of the frequency converter are monitored in real time through the digital storage oscillograph and are finally transmitted to the terminal and are stored through the data storage unit, and then the changes of the electrical quantities of different frequency converters in a specified voltage reduction environment within specified time can be compared in detail. Therefore, the electrical quantity change can be conveniently analyzed, and the frequency converter which operates most stably under low voltage, namely, has the best low-voltage ride-through capability is selected.

Description

Technical Field

[0001] The invention belongs to the field of frequency converter testing, in particular to a frequency converter low voltage ride-through capability testing system. Background Art

[0002] The inverter provides the required power voltage according to the actual needs of the motor, thereby achieving the purpose of energy saving and speed regulation. In addition, the inverter has many protection functions, such as over-current, over-voltage, overload protection, etc. With the continuous improvement of industrial automation, the inverter has also been widely used.

[0003] However, in actual use, the inverter will be in a low voltage state when the power grid is unstable, there is a sudden power outage or other emergencies. If this may cause failure or even scrapping, the inverter needs to have a certain low voltage ride-through capability to ensure that the system will not be damaged or scrapped due to low voltage. Especially in industrial production, it is often necessary to ensure that the equipment operates continuously for several hours or days. Once it stops, it will cause great losses to production. Therefore, improving the low voltage ride-through capability of the inverter is an important means to ensure the safe operation of the equipment and reduce losses.

[0004] At present, the low voltage ride-through capability test of the inverter is an important performance test item of the inverter performance test. At present, most tests judge the low voltage ride-through capability of the inverter by reducing the voltage to a specified time and observing whether the inverter can operate normally. However, although the above operation can judge whether the low voltage ride-through capability of the inverter meets the standard, its own judgment method is that the inverter can operate normally when it is reduced to a specified voltage for a specified time, but it is not possible to make an effective comparison of qualified inverters. At the same time, although some inverters can operate normally, if the electrical quantities of the inverter under low voltage are unconventional, there may be hidden dangers in subsequent use. At the same time, the current detection system also lacks safety protection measures in case of inverter failure or even explosion during the detection process. Summary of the invention

[0005] The invention provides a frequency converter low voltage ride-through capability testing system to solve the defects in the prior art.

[0006] The present invention is achieved through the following technical solutions:

[0007] A frequency converter low voltage ride-through capability test system, comprising a test module, a control module, a protection module, a warning module and a terminal;

[0008] The test module includes a three-phase rectifier unit, a three-phase controllable inverter unit, a digital storage recorder and a simulated load unit;

[0009] The control module includes a processing unit, a voltage control unit, a digital storage recorder signal receiving unit, a warning module control unit and a protection module control unit;

[0010] The warning module includes a warning unit;

[0011] The terminal can receive the information delivered by the control module and store the data through the data storage unit.

[0012] As described above, a frequency converter low voltage ride-through capability test system, the test module is connected to the municipal power supply through the three-phase rectifier unit and the three-phase controllable inverter unit to conveniently complete the voltage control, thereby effectively completing the low voltage ride-through capability test after connecting to the frequency converter, and at the same time, by connecting to the simulation load unit, the low voltage ride-through capability test of the frequency converter under the condition of connecting to the relevant load during actual use is simulated, the two ends of the digital storage recorder are respectively connected to the two ends of the frequency converter, and the digital storage recorder is used to monitor the changes of various electrical quantities of the frequency converter in real time and transmit the signal to the digital storage recorder signal receiving unit in real time, the digital storage recorder signal receiving unit transmits the signal to the processing unit, the processing unit transmits the signal to the terminal in real time by wireless communication, and the terminal receives the signal and transcodes it and saves it to the data storage unit for data storage.

[0013] In the inverter low voltage ride-through capability testing system as described above, the power of the simulated load unit is 500-30000W.

[0014] In the inverter low voltage ride-through capability test system as described above, the processing unit can control the three-phase rectifier unit and the three-phase controllable inverter unit through the voltage control unit to complete the voltage reduction operation, and the processor performs the voltage reduction operation in sequence according to the preset voltage reduction amplitude and maintenance time, thereby automatically completing the inverter low voltage ride-through capability test system.

[0015] In the inverter low voltage ride-through capability test system as described above, the processing unit receives the changes of various electrical quantities of the inverter transmitted by the digital storage recorder through the digital storage recorder signal receiving unit. At the same time, when abnormal changes occur, the processing unit finds the abnormality and then controls the warning unit of the warning module to issue a warning prompt through the warning module control unit. At the same time, the processing unit will also transmit the information to the terminal, and the terminal will issue a warning to the mobile phone or monitoring computer of the relevant personnel, so as to avoid accidents.

[0016] In the inverter low voltage ride-through capability testing system as described above, the warning unit is a buzzer alarm.

[0017] As described above, in a frequency converter low voltage ride-through capability test system, the protection module includes an electric control switch arranged on the three-phase lines at the front and rear ends of the frequency converter, and when the processing unit receives various electrical quantities of the frequency converter transmitted by the digital storage recorder through the digital storage recorder signal receiving unit and shows abnormalities, the processing unit can control the electric control switch to be completely disconnected through the protection module control unit to avoid accidents.

[0018] In the inverter low voltage ride-through capability testing system as described above, the protection module also includes a fire extinguishing device.

[0019] In the inverter low voltage ride-through capability test system as described above, the fire extinguishing device includes a plurality of dust fire extinguishing nozzles with smoke temperature sensors arranged above the inverter.

[0020] In the inverter low voltage ride-through capability test system as described above, the data storage unit stores the changes of various electrical quantities under different step-down environments under the low voltage ride-through capability test of each inverter under the corresponding production batch number, so as to facilitate subsequent comparison and selection of the inverter with the best performance.

[0021] The advantages of the present invention are:

[0022] 1. In the present invention, the changes of various electrical quantities of the inverter are monitored in real time by a digital storage recorder and finally transmitted to the terminal and stored by a data storage unit. Then, the changes of various electrical quantities of different inverters within a specified time under a specified step-down environment can be compared in detail, so that the changes of electrical quantities can be conveniently analyzed to select the inverter with the most stable operation under low voltage, that is, the best low voltage ride-through capability, so that the qualified inverter can be further analyzed to ensure the stability during subsequent use;

[0023] 2. The present invention is provided with a control module, a protection module and a warning module. When the digital storage recorder monitors the various electrical quantity changes of the inverter in real time and shows abnormalities, the power can be cut off in time and a warning can be issued to avoid accidents. At the same time, if a fire does occur, the fire control box can be quickly extinguished through the provided fire extinguishing device to avoid casualties. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] A frequency converter low voltage ride-through capability test system, comprising a test module, a control module, a protection module, a warning module and a terminal;

[0026] The test module includes a three-phase rectifier unit, a three-phase controllable inverter unit, a digital storage recorder and a simulated load unit;

[0027] The control module includes a processing unit, a voltage control unit, a digital storage recorder signal receiving unit, a warning module control unit and a protection module control unit;

[0028] The warning module includes a warning unit;

[0029] The terminal can receive the information delivered by the control module and store the data through the data storage unit.

[0030] Specifically, the test module described in this embodiment is connected to municipal electricity through a three-phase rectifier unit and a three-phase controllable inverter unit, which can easily complete the voltage control, thereby effectively completing the low voltage ride-through capability test after connecting to the inverter. At the same time, by connecting to the simulated load unit, the low voltage ride-through capability test of the inverter is simulated when connected to the relevant load during actual use. The two ends of the digital storage recorder are respectively connected to the two ends of the inverter. The digital storage recorder is used to monitor the changes of various electrical quantities of the inverter in real time and transmit the signal to the digital storage recorder signal receiving unit in real time. The digital storage recorder signal receiving unit transmits the signal to the processing unit, and the processing unit transmits the signal to the terminal in real time through wireless communication. After the terminal receives the signal, it transcodes and saves it to the data storage unit for data storage.

[0031] Specifically, the power of the simulated load unit described in this embodiment is 500-30000W.

[0032] More specifically, the processing unit described in this embodiment can control the three-phase rectifier unit and the three-phase controllable inverter unit through the voltage control unit to complete the voltage reduction operation. The processor performs the voltage reduction operation in sequence according to the preset voltage reduction amplitude and maintenance time, thereby automatically completing the inverter low voltage ride-through capability test system.

[0033] More specifically, the processing unit described in this embodiment receives changes in various electrical quantities of the inverter transmitted by the digital storage recorder through the digital storage recorder signal receiving unit. At the same time, when abnormal changes occur, the processing unit finds the abnormality and then controls the warning unit of the warning module through the warning module control unit to issue a warning prompt. At the same time, the processing unit will also transmit the information to the terminal, and the terminal will issue a warning to the mobile phone or monitoring computer of the relevant personnel to avoid accidents.

[0034] More specifically, the warning unit described in this embodiment is a buzzer alarm.

[0035] Furthermore, the protection module described in this embodiment includes an electric control switch arranged on the three-phase line at the front and rear ends of the inverter. When the processing unit receives various electrical quantities of the inverter transmitted by the digital storage recorder through the digital storage recorder signal receiving unit and shows abnormalities, it can control the electric control switch to be disconnected through the protection module control unit to avoid accidents.

[0036] Furthermore, the protection module described in this embodiment also includes a fire extinguishing device.

[0037] Furthermore, the fire extinguishing device described in this embodiment includes a plurality of dust fire extinguishing nozzles with smoke temperature sensors arranged above the frequency converter.

[0038] Furthermore, the data storage unit described in this embodiment stores the changes in various electrical quantities under different step-down environments under the corresponding low voltage ride-through capability test of each tested inverter under the corresponding production batch number, thereby facilitating subsequent comparison and selection of the inverter with the best performance.

[0039] Finally, 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A frequency converter low voltage ride-through capability test system, characterized by: It includes a test module, a control module, a protection module, a warning module and a terminal; The test module includes a three-phase rectifier unit, a three-phase controllable inverter unit, a digital storage recorder and a simulated load unit; The control module includes a processing unit, a voltage control unit, a digital storage recorder signal receiving unit, a warning module control unit and a protection module control unit; The warning module includes a warning unit; The terminal can receive the information delivered by the control module and store the data through the data storage unit.

2. The inverter low voltage ride-through capability test system according to claim 1, characterized in that: The test module is connected to municipal electricity through a three-phase rectifier unit and a three-phase controllable inverter unit, which can easily complete voltage control, thereby effectively completing the low voltage ride-through capability test after connecting to the inverter. At the same time, by connecting to a simulated load unit, the low voltage ride-through capability test of the inverter is simulated when connected to relevant loads during actual use. The two ends of the digital storage recorder are respectively connected to the two ends of the inverter. The digital storage recorder monitors the changes of various electrical quantities of the inverter in real time and transmits the signal to the digital storage recorder signal receiving unit in real time. The digital storage recorder signal receiving unit transmits the signal to the processing unit. The processing unit transmits the signal to the terminal in real time by wireless communication. After the terminal receives the signal, it transcodes and saves it to the data storage unit for data storage.

3. The inverter low voltage ride-through capability test system according to claim 1, characterized in that: The power of the simulated load unit is 500-30000W.

4. The inverter low voltage ride-through capability test system according to claim 1, characterized in that: The processing unit can control the three-phase rectifier unit and the three-phase controllable inverter unit through the voltage control unit to complete the voltage reduction operation. The processor performs the voltage reduction operation in sequence according to the preset voltage reduction amplitude and maintenance time, thereby automatically completing the inverter low voltage ride-through capability test system.

5. The inverter low voltage ride-through capability test system according to claim 1, characterized in that: The processing unit receives the changes of various electrical quantities of the inverter transmitted by the digital storage recorder through the digital storage recorder signal receiving unit. At the same time, when abnormal changes occur, the processing unit finds the abnormality and controls the warning unit of the warning module through the warning module control unit to issue a warning prompt. At the same time, the processing unit will also transmit the information to the terminal, and the terminal will issue a warning to the mobile phone or monitoring computer of the relevant personnel to avoid accidents.

6. The inverter low voltage ride-through capability test system according to claim 1, characterized in that: The warning unit is a buzzer alarm.

7. The inverter low voltage ride-through capability test system according to claim 1, characterized in that: The protection module includes an electric control switch arranged on the three-phase lines at the front and rear ends of the inverter. When the processing unit receives various electrical quantities of the inverter transmitted by the digital storage recorder through the digital storage recorder signal receiving unit and shows abnormalities, it can control the electric control switches to be disconnected through the protection module control unit to avoid accidents.

8. The inverter low voltage ride-through capability test system according to claim 7, characterized in that: The protection module also includes a fire extinguishing device.

9. The inverter low voltage ride-through capability test system according to claim 8, characterized in that: The fire extinguishing device comprises a plurality of dust fire extinguishing nozzles with smoke temperature sensors arranged above the frequency converter.

10. The inverter low voltage ride-through capability test system according to claim 1, characterized in that: The data storage unit stores the changes of various electrical quantities under different step-down environments under the corresponding low voltage ride-through capability test for each tested inverter under the corresponding production batch number, so as to facilitate subsequent comparison and selection of the inverter with the best performance.