CN104569801A - Characteristic test device and method for alternating-and-direct-current dual-purpose low-voltage circuit breaker - Google Patents

Abstract

The present invention provides a characteristic test device and method for AC and DC dual-purpose low-voltage circuit breakers, including an AC test power supply for supplying power to the low-voltage circuit breaker and a complete set of multi-magnetic circuit transformers. The DC test circuit selector switch is respectively connected with the AC circuit breaker characteristic test bench and the DC circuit breaker characteristic test bench, and the AC circuit breaker characteristic test bench and the DC circuit breaker characteristic test bench are respectively connected with the data acquisition unit and the programmable The controller PLC is connected, and the output terminal of the programmable controller PLC is connected with the complete set of multi-magnetic circuit transformers to control the voltage level of the current source. The device of the invention is used for detecting the characteristics of the low-voltage circuit breaker, and can reliably and efficiently complete the characteristic test and detection of the AC or DC circuit breaker.

Description

A characteristic test device and method for AC and DC dual-purpose low-voltage circuit breakers

【Technical field】

The invention belongs to the technical field of detection of low-voltage circuit breakers, and in particular relates to detection of characteristics of a circuit breaker, especially detection of operating current and operating time of a low-voltage circuit breaker.

【Background technique】

Circuit breakers are indispensable and important equipment in the field of low-voltage electrical appliances, and their operating current and operating time are the two main indicators of circuit breakers. The fixed value of the circuit breaker is mainly completed by adjusting the tension spring and the adjustable potentiometer. Due to working hours, vibration, repair and other reasons, the setting value of the circuit breaker will often change, which may easily cause protection or malfunction, resulting in the expansion of the fault range of the electrical system or the malfunction of the equipment. Therefore, it is of great practical significance to develop large circuit breaker characteristic test equipment to regularly check and verify some characteristic parameters of the circuit breaker to ensure the sensitivity and reliability of its work. The low-voltage circuit breaker test bench is a test device designed to complete the circuit breaker characteristic setting. Due to the large test current and the need for action detection of AC circuit breakers and DC circuit breakers, the design of the test device is difficult.

The commonly used low-voltage AC circuit breaker operating characteristic test bench in the early days mostly used the combination of induction voltage regulator and low-voltage high-current transformer, that is, AC current → induction voltage regulator → low-voltage high-current transformer → test circuit breaker. This mode has three defects: (1) The capacity of the voltage regulator is required to be large enough, resulting in bulky equipment; (2) Due to the large capacity of the voltage regulator, only the induction voltage regulator can be used, and the induction voltage regulator will cause The waveform distortion is high; (3) the test current is not easy to control, and the test error is large. The low-voltage DC circuit breaker operating characteristics test bench mostly uses DC generator sets, and uses AC power to cooperate with the generator set to realize current output. The advantage is that the ripple coefficient of the power supply is small and the quality is good; the disadvantage is that the unit is bulky, difficult to maintain, and high in cost. , running noisy. The principle structure of the commonly used AC circuit breaker and DC circuit breaker characteristic test bench is shown in Figure 1. 1 is the AC power supply, which is the power input of the whole test bench, 2 is the induction voltage regulator, and 3 is the low-voltage high-current transformer, which is used in conjunction with the induction voltage regulator 2 in the AC test bench to realize the output of AC large current, and 4 is the AC test Circuit breaker 5 is a DC generator set, which provides DC current for the DC characteristic test circuit breaker, and 6 is a DC test circuit breaker.

【Content of invention】

The object of the present invention is to provide a characteristic test device and method for AC and DC dual-purpose low-voltage circuit breakers, which can accurately and reliably complete the inspection of the operating current and operating time of the low-voltage circuit breaker.

The purpose of the present invention is solved by the following technical solutions:

A characteristic test device for AC and DC dual-purpose low-voltage circuit breakers, including an AC test power supply for supplying power to the low-voltage circuit breaker and a complete set of multi-magnetic circuit transformers. respectively connected with the AC circuit breaker characteristic test bench and the DC circuit breaker characteristic test bench, the AC circuit breaker characteristic test bench and the DC circuit breaker characteristic test bench are respectively connected with the data acquisition unit and the programmable controller PLC through the power transmitter, The output terminal of the programmable controller PLC is connected with the complete set of multi-magnetic circuit transformers to control the voltage level of the current source.

The AC test power supply is connected to the complete set of multi-magnetic circuit transformers through an optional closing switch to prevent inrush current.

The multi-magnetic circuit transformer complete set includes at least a multi-magnetic circuit conversion device for voltage coarse adjustment and a three-phase auto-coupling voltage regulator for voltage fine adjustment, and the programmable controller PLC is connected with the multi-magnetic circuit conversion device respectively Connect with a three-phase autotransformer.

The multi-magnetic circuit transformer complete set includes at least a multi-magnetic circuit conversion device for voltage coarse adjustment and a three-phase auto-coupling voltage regulator for voltage fine adjustment, and the programmable controller PLC is connected with the multi-magnetic circuit conversion device respectively , Three-phase auto-coupling voltage regulator, and optional closing switch connection.

The AC/DC test circuit selector switch is connected to the DC circuit breaker characteristic test bench sequentially through a rectifier device and a shunt.

The data acquisition unit adopts PCI-1716L high-speed data acquisition card, which has a 16-bit A/D converter, provides 16 single-ended analog inputs or 8 differential analog inputs, and has two 16-bit D/A output channel, 16-bit digital input/output channel and 1 16-bit counter channel.

A method for testing the characteristics of AC and DC dual-purpose low-voltage circuit breakers. First, the PLC determines the voltage level according to the output requirements, and sends the instruction of the voltage level to the complete set of multi-magnetic circuit transformers. Then, after the AC test power supply is connected, the AC test power supply The voltage provided is converted to the specified voltage level output in the multi-magnetic circuit transformer complete set, the AC and DC test circuit selection switch is switched to the corresponding test system according to the type of test, and then the output result is transmitted to the programmable controller through the power transmitter The programmable controller PLC compares the preset value with the collected output result. If it is inconsistent with the preset value, it will issue an instruction to the multi-magnetic circuit transformer complete set to adjust the voltage until the preset value is consistent with the collected value. .

The AC test power supply first passes through the optional closing switch and then is provided to the complete set of multi-magnetic circuit transformers. The optional closing switch performs closing action only when the AC voltage crosses zero, and provides the voltage to the complete set of multi-magnetic circuit transformers.

The multi-magnetic circuit transformer complete set includes at least a multi-magnetic circuit conversion device for voltage coarse adjustment and a three-phase auto-coupling voltage regulator for voltage fine adjustment, and the programmable controller PLC determines the coarse The voltage regulation is fine regulation voltage or the combination of coarse regulation voltage and fine regulation voltage to ensure stable current output.

Compared with the prior art, the present invention has at least the following beneficial effects: the device current source of the present invention includes a complete set of multi-magnetic circuit transformers, so that the capacity of the voltage regulator is greatly reduced, and the volume of the voltage regulator is greatly reduced; The capacity of the voltage regulator is greatly reduced. Therefore, an autovoltage regulator can be used to greatly reduce the waveform distortion of the test voltage output. In addition, the device of the present invention can realize both AC and DC tests by using one current source.

【Description of drawings】

Figure 1 is a schematic diagram of an existing AC/DC circuit breaker characteristic test bench;

Fig. 2 is a schematic diagram of a characteristic test device for AC and DC dual-purpose low-voltage circuit breakers of the present invention.

In the figure: 1 is the AC test power supply, 2 is the induction voltage regulator, 3 is the low-voltage high-current transformer, 4 is the AC test circuit breaker, 5 is the DC generator set, 6 is the DC test circuit breaker, 7 is the phase selection switch, 8 is a multi-magnetic circuit conversion device, 9 is a three-phase multi-magnetic circuit transformer, 10 is an industrial computer, 11 is a programmable controller PLC, 12 is a three-phase auto-coupling voltage regulator, 13 is an AC/DC test circuit selection switch, 14 15 is a shunt, 16 is a test bench for AC circuit breaker characteristics, 17 is a test bench for DC circuit breaker characteristics, 18 is a power transmitter, 19 is a data acquisition system, 20 is a power meter, and 21 is a test control power supply .

【Detailed ways】

Below in conjunction with accompanying drawing 2 the present invention is described in further detail:

At present, the multi-magnetic circuit transformer technology has been developed rapidly, and the PLC control technology has matured. The action characteristic test of the low-voltage circuit breaker is controlled by the multi-magnetic circuit transformer complete set of devices as the core of the power supply, and the centralized control is carried out on the industrial computer through the PLC using the distributed control method. , together with the self-coupling voltage regulator to realize the automatic steady flow function. This type of test mode has the following advantages: (1) The capacity of the voltage regulator is greatly reduced by using a complete set of multi-magnetic circuit transformers; (2) Due to the reduction of the capacity of the voltage regulator, An auto-coupling voltage regulator can be selected to make the distortion of the test voltage output waveform small; (3) In this test mode, the function of the auto-coupling voltage regulator is only equivalent to fine adjustment, and the multi-magnetic circuit transformer and multi-pole transformer The input of each level is equivalent to coarse adjustment, which makes the test current easy to control and the accuracy of steady current is higher. On the power input side, the closing angle is controlled by the phase selection closing switch, which reduces the component of the inrush current during the transient test and improves the accuracy of the results. Combined with the use of the AC and DC test circuit selection switch, one machine can be used for two purposes, and the characteristic detection of different types of circuit breakers can be completed.

Referring to Fig. 2, the AC-DC dual-purpose low-voltage circuit breaker characteristic test device of the present invention comprises an AC test power supply 1, a complete set of multi-magnetic circuit transformers, an AC-DC test circuit selection switch 13, through which different test circuits are selected, and the circuit breaker The characteristic test benches are used to conduct characteristic tests of different types of circuit breakers. The data acquisition system 19 uploads the data collected by the power transmitter 18 through cables, and the data are respectively sent to the industrial computer 10 and the programmable control system of the test control system. device PLC11, and the other road is directly sent to the electricity meter 20 to realize real-time display. The multi-magnetic circuit transformer complete set is mainly composed of a multi-magnetic circuit conversion device 8 , a three-phase autovoltage regulator 12 and a three-phase multi-magnetic circuit transformer 9 . ,

Concrete connection relation of the present invention is as follows:

In the AC circuit breaker characteristic test, in order to avoid the influence of the inductive reactance in the test circuit on the large current test, the phase selection closing switch 7 is selected to close the AC test power supply at about 90° to reduce the impact current component in the test circuit. When closing the switch, first use the voltage transformer attached to the phase selection closing device to perform voltage sampling. When the voltage crosses zero, the switch is closed according to the command issued by the programmable controller PLC11. The programmable controller PLC11 is controlled by the industrial computer 10. According to the program setting, the control power required by the industrial computer 10 is provided by the test control power supply 21 . The output cable of the phase selection closing switch 7 is connected to the multi-magnetic circuit conversion device 8 to realize different voltage outputs to change different output current values. The multi-magnetic circuit conversion device 8 is equipped with a multi-stage transformer. The current command is automatically adjusted to realize the selection of different magnetic circuits and the rough adjustment of the current selection range. The current output is realized through the three-phase multi-magnetic circuit transformer 9. The AC and DC test circuit selection switch 13 is selected as the AC test, and the current is directly sent to the In the AC circuit breaker characteristic test bench 16, the characteristic test bench is connected to the test product, and the relevant information of the current is collected through the power transmitter 18, and the collected information is output through three channels respectively, and the current value of one channel is directly displayed on the power meter 20. On the meter head of the device, one path is sent to the programmable controller PLC11 for sampling, and the other path is a tracking model and sent to the industrial computer 10 through the data acquisition system 19 for waveform display and analysis. USB communication is adopted between the industrial computer 10 and the programmable controller PLC11. The data acquisition system 19 adopts PCI-1716L high-speed data acquisition card sampling, which has a 16-bit A/D converter, which can provide 16 single-ended analog inputs or 8 differential analog inputs, and can also combine inputs. There are 2 16-bit D/A output channels, 16-bit digital input/output channels and 1 16-bit counter channel. The analysis and control software is written in the industrial computer 10. The software adopts VC++6.0 programming to realize data acquisition, storage and waveform display, and communicates interactively with the programmable controller PLC12. The software uses interrupt technology to realize fast data sampling in turn. In order to facilitate the real-time observation of parameter changes in the test process in the data acquisition and processing system, and to better analyze the acquisition waveform accurately, in the design and development process of the system program, ACT series communication controls are selected. ACT series controls are based on the MELSEC communication protocol independently developed by MITSUBISHI for data communication. The industrial computer 10 can read/write PLC device data and sequential control programs through the ACT control, and can also monitor the equipment status of the programmable controller PLC11, and continuously analyze the collected real-time current. Compared with the collected real-time current, the three-phase autovoltage regulator 12 is automatically adjusted to realize the fine adjustment of the current output, so as to achieve the effect of steady current.

When conducting the DC circuit breaker characteristic test, the working structures of the two are similar. The AC-DC test circuit selection switch 13 is selected as the DC test, and the rectifier device 14 is connected accordingly to realize the AC-DC current conversion, and relevant current signals are collected through the shunt 15 , the current is directly sent to the DC circuit breaker characteristic test bench 17 through the cable, the characteristic test bench is connected to the test product, and relevant current information is collected through the power transmitter 18, which is similar to the AC control principle.

In summary, the AC/DC dual-purpose low-voltage circuit breaker characteristic test device of the present invention starts processing from the power input, reduces the impact component of the circuit through the use of the phase selection closing switch, and at the same time combines the AC and DC test circuit selection switch to realize a machine Dual-purpose, the core control adopts industrial computer and programmable controller, combined with the data reported by the data acquisition system to realize the automatic control of the test loop, the test current information can be displayed in real time, the industrial computer displays the test results and waveforms, the operation is simple and easy to use, reducing the The working intensity of the test personnel has improved the test efficiency, turned the passive maintenance of the low-voltage circuit breaker into active maintenance, and ensured that the circuit breaker can work stably for a long time. The circuit breaker verified by the test equipment can greatly improve the safety of the electrical equipment and the power system, which is of great significance.

This patent is aimed at the characteristics of low-voltage circuit breakers, and its current parameters can reach 40kA, which meets most of the circuit breakers on the market.

The present invention has the following beneficial effects:

1) The phase-selection closing switch is used to eliminate the non-periodic component of the test current to the greatest extent during the transient test and reduce the impact current component.

2) Using a multi-magnetic circuit transformer as the power supply reduces the capacity of the voltage regulator and realizes high-precision control of current output.

3) Through the use of the selector switch of the AC and DC test circuit, it is convenient to realize the dual-purpose of the characteristic test bench and expand its practicability.

4) The present invention adopts industrial computer and programmable logic controller PLC to cooperate to use, realizes the integrated application of control and measurement, improves test efficiency.

Claims (9)

1. an AC/DC low-voltage circuit breaker characteristic test apparatus, it is characterized in that: comprise for low-voltage circuit breaker provides AC-testing supply and the multiple magnetic circuit transformer complete equipment of power supply, the output terminal of described multiple magnetic circuit transformer complete equipment is connected with AC circuit breaker attribute testing platform and DC circuit breaker attribute testing platform respectively by alternating current-direct current test loop selector switch, described AC circuit breaker attribute testing platform is connected with data acquisition unit and programmable controller PLC by electric parameters transducer respectively with DC circuit breaker attribute testing platform, the output terminal of described programmable controller PLC is connected the electric pressure to control current source with multiple magnetic circuit transformer complete equipment.

2. AC/DC low-voltage circuit breaker characteristic test apparatus according to claim 1, is characterized in that: described AC power is connected to prevent from shoving with multiple magnetic circuit transformer complete equipment by option closing switch.

3. AC/DC low-voltage circuit breaker characteristic test apparatus according to claim 1, it is characterized in that: described multiple magnetic circuit transformer complete equipment at least comprise the multipath magnetic circuit conversion equipment for voltage coarse adjustment and the three-phase automatic coupling voltage regulator for voltage fine, and described programmable controller PLC is connected with multipath magnetic circuit conversion equipment and three-phase automatic coupling voltage regulator respectively.

4. AC/DC low-voltage circuit breaker characteristic test apparatus according to claim 2, it is characterized in that: described multiple magnetic circuit transformer complete equipment at least comprise the multipath magnetic circuit conversion equipment for voltage coarse adjustment and the three-phase automatic coupling voltage regulator for voltage fine, described programmable controller PLC respectively with multipath magnetic circuit conversion equipment, three-phase automatic coupling voltage regulator, and option closing switch connect.

5. AC/DC low-voltage circuit breaker characteristic test apparatus according to claim 1, is characterized in that: described alternating current-direct current test loop selector switch is connected with DC circuit breaker attribute testing platform with shunt by fairing successively.

6. AC/DC low-voltage circuit breaker characteristic test apparatus according to claim 1, it is characterized in that: described data acquisition unit adopts PCI-1716L high-speed data acquisition card, himself is with 16 A/D converters, 16 road single-ended analog amount inputs or 8 road difference analogue amount inputs are provided, simultaneously with 2 16 D/A output channels, 16 bit digital quantity I/O passages and 1 16 digit counter passage.

7. the AC/DC low-voltage circuit breaker characteristic test method based on device described in any one in claim 1 to 6, it is characterized in that: first PLC is according to the requirement determination electric pressure exported, multiple magnetic circuit transformer complete equipment are issued in the instruction of this electric pressure, then, after connecting AC-testing supply, the voltage that AC-testing supply provides is converted into the electric pressure of specifying at multiple magnetic circuit transformer complete equipment and exports, alternating current-direct current test loop selector switch is switched to corresponding pilot system according to the type of test, then Output rusults is transferred to programmable controller PLC by electric parameters transducer, programmable controller PLC contrasts according to the Output rusults of the numerical value preset and collection, if inconsistent with the numerical value preset, then send instruction to regulate voltage until preset value is consistent with collection value to multiple magnetic circuit transformer complete equipment.

8. method according to claim 7, it is characterized in that: AC-testing supply is first through option closing switch and then be supplied to multiple magnetic circuit transformer complete equipment, described option closing switch only carries out feed motion when the zero crossing of alternating voltage, voltage is supplied to multiple magnetic circuit transformer complete equipment.

9. method according to claim 7, it is characterized in that: described multiple magnetic circuit transformer complete equipment at least comprise the multipath magnetic circuit conversion equipment for voltage coarse adjustment and the three-phase automatic coupling voltage regulator for voltage fine, the type determination coarse tuning voltage of described programmable controller PLC according to test product or the combination of fine tuning voltage or coarse tuning voltage and fine tuning voltage, to ensure the output of current stabilization.