阅读说明：本技术 剩余电流模拟生成装置及剩余电流动作保护系统 (Residual current simulation generation device and residual current action protection system ) 是由 赵宇明 王静 刘国伟 陈思磊 谢智敏 于 2019-09-24 设计创作，主要内容包括：本申请涉及一剩余电流模拟生成装置及剩余电流动作保护系统。上述剩余电流模拟生成装置,包括第一直流变换器、并联于所述直流变换器两端的剩余电流模拟器以及电连接于所述直流变换器与所述剩余电流模拟器之间的开关器。当所述开关器闭合后,直流变换器输出电压,并且所述剩余电流模拟器的阻值可以匀速稳定变化,在一定时间内,可以使通过所述剩余电流模拟器的剩余电流较小的值稳定增加至额定直流剩余动作电流标准值,由此得到一个直流剩余电流曲线。所述剩余电流模拟生成装置能够实现对直流系统剩余电流动作保护器的性能进行有效地试验,提升其产品质量,进而提升直流系统安全的稳定运行能力。(The application relates to a residual current simulation generation device and a residual current action protection system. The residual current simulation generation device comprises a first direct current converter, a residual current simulator connected in parallel to two ends of the direct current converter and a switch electrically connected between the direct current converter and the residual current simulator. After the switch is closed, the direct current converter outputs voltage, the resistance value of the residual current simulator can stably change at a constant speed, and the smaller value of the residual current passing through the residual current simulator can be stably increased to a rated direct current residual action current standard value within a certain time, so that a direct current residual current curve is obtained. The residual current simulation generation device can effectively test the performance of the residual current action protector of the direct current system, improve the product quality of the residual current action protector and further improve the safe and stable operation capability of the direct current system.)

1. A residual current simulation generation device, comprising:

a first DC converter (110) electrically connected to a municipal AC power source;

a residual current simulator (120) connected in parallel across the first DC converter (110); and

and the switch (130) is electrically connected between the first direct current converter (110) and the residual current simulator (120), and when the switch (130) is closed, direct current residual currents with different waveforms are generated by the residual current simulator (120).

2. The residual current simulation generation device according to claim 1, characterized in that the residual current simulator (120) comprises:

a second DC converter (121) electrically connected to a municipal AC power supply;

a controller (122) electrically connected to the second DC converter (121); and

a controlled current source (123) electrically connected to the second DC converter (121) and the controller (122), respectively, and the switch (130) is electrically connected between the first DC converter (110) and the controlled current source (123).

3. The residual current simulation generating device according to claim 2, wherein the switch (130) comprises:

a first gating switch (131) electrically connected between a first terminal of the controlled current source (123) and the first DC converter (110); and

a second gating switch (132) electrically connected between the second terminal of the controlled current source (123) and the first DC converter (110).

4. The residual current simulation generation apparatus according to claim 3, further comprising:

and a first breaker (141) electrically connected between the second DC converter (121) and a municipal AC power source.

5. The residual current simulation generation apparatus according to claim 4, further comprising:

and a DC feedback load (150) connected to the first DC converter (110) to form a DC main circuit.

6. The residual current simulation generation apparatus according to claim 5, further comprising:

a second circuit breaker (142) electrically connected between a first end of the DC flyback load (150) and the first DC converter (110); and

and a third circuit breaker (143) electrically connected between the second end of the DC feedback load (150) and the first DC converter (110).

7. The residual current simulation generation apparatus according to claim 6, further comprising:

and the voltage detection device (160) is electrically connected to two ends of the first direct current converter (110) and is used for detecting the output voltage of the first direct current converter (110).

8. The residual current simulation generation apparatus according to claim 7, further comprising:

and the current detection device (170) is electrically connected between the second end of the controlled current source (123) and the second gating switch (132).

9. The residual current simulation generating device according to claim 8, wherein the voltage detecting device (160) is a voltage sensor and the current detecting device (170) is a hall current sensor.

10. The residual current simulation generation device according to claim 9, wherein the input voltage of the first dc converter (110) is ac 380V, the output voltage of the first dc converter (110) is dc 90V to 400V, and the rated current of the first dc converter (110) is 150A.

11. A residual current operated protection system, comprising:

a residual current simulation generating device (10) as claimed in any one of claims 1 to 10; and

and the direct current residual current action protector (210) is electrically connected with the residual current simulation generation device (10).

Technical Field

The present disclosure relates to electrical devices, and particularly to a residual current simulation device and a residual current operation protection system.

Background

With the implementation of national energy-saving and emission-reducing policies, a large number of photovoltaic power systems, energy storage systems, electric vehicles and the like are connected to a power distribution network, and the power distribution and utilization trend is shown in a direct current trend. However, the residual electricity causes personal electric shock, damages of power supply equipment and even fire, which causes a great deal of personal casualties and huge economic loss, so that the safe power utilization is more and more emphasized by people. The aging of the lead or the damage of the insulating layer, the nonstandard construction, the violent construction and the like are all reasons for the occurrence of residual current. When a residual current occurs in the line, the line may be burned, causing an electrical fire accident. Meanwhile, when a human body directly contacts a conductor through which residual current flows, an electric shock accident can be caused, and the life safety of the human body is seriously threatened. However, the quality of the existing residual current operated protectors for the direct current system in China is not uniform, and the construction and development of the direct current power supply field in China are severely restricted. Therefore, the high-precision direct current residual current simulation method with controllable polarity can effectively test the performance of the residual current operated protector for the direct current system, improve the product quality of the residual current operated protector and improve the safe and stable operation capability of the direct current system.

In 2017, international standard IEC TS 63053 drafted by the International electrotechnical Commission, 2017 general requirements for residual current operated protective electric appliances for direct current systems, and provisions are mainly made on the characteristics and classification of residual current operated protective devices for direct current systems. But China does not have standards related to the residual current operated protector for the direct current system at present. In addition, the traditional residual current generating device for the alternating current system cannot test the direct current residual current operated protector and has the problem of low control precision.

Disclosure of Invention

Therefore, it is necessary to provide a residual current analog generation device and a residual current operation protection system for solving the problems that the conventional residual current generation device for the ac system cannot test the dc residual current operation protector and has low control accuracy.

A residual current simulation generation device, comprising:

the first direct current converter is electrically connected with a municipal alternating current power supply;

the residual current simulator is connected in parallel to two ends of the first direct current converter; and

and the switch is electrically connected between the first direct current converter and the residual current simulator, and when the switch is closed, direct current residual currents with different waveforms are generated by the residual current simulator.

In one embodiment, the residual current simulator comprises:

the second direct current converter is electrically connected with the municipal alternating current power supply;

a controller electrically connected to the second dc converter; and

and the controlled current source is electrically connected with the second direct current converter and the controller respectively, and the switch is electrically connected between the first direct current converter and the controlled current source.

In one embodiment, the switch comprises:

a first gating switch electrically connected between a first end of the controlled current source and the first DC converter; and

and the second gating switch is electrically connected between the second end of the controlled current source and the first direct current converter.

In one embodiment, the method further comprises the following steps:

and the first circuit breaker is electrically connected between the second direct current converter and a municipal alternating current power supply.

In one embodiment, the method further comprises the following steps:

and the direct current feedback load is connected with the first direct current converter to form a direct current main loop.

In one embodiment, the method further comprises the following steps:

the second circuit breaker is electrically connected between the first end of the direct current feedback load and the first direct current converter; and

and the third circuit breaker is electrically connected between the second end of the direct current feedback load and the first direct current converter.

In one embodiment, the method further comprises the following steps:

and the voltage detection device is electrically connected to two ends of the first direct current converter and is used for detecting the output voltage of the first direct current converter.

In one embodiment, the method further comprises the following steps:

and the current detection device is electrically connected between the second end of the controlled current source and the second gating switch.

In one embodiment, the voltage detection device is a voltage sensor, and the current detection device is a hall current sensor.

In one embodiment, the input voltage of the first dc converter is 380V ac, the output voltage of the first dc converter is 90V to 400V dc, and the rated current of the first dc converter is 150A.

A residual current operated protection system comprising:

the residual current simulation generation device of any one of the above embodiments; and

and the direct current residual current action protector is electrically connected with the residual current simulation generation device.

The residual current simulation generation device comprises a first direct current converter, a residual current simulator connected in parallel to two ends of the direct current converter and a switch electrically connected between the direct current converter and the residual current simulator. After the switch is closed, the direct current converter outputs voltage, the resistance value of the residual current simulator can stably change at a constant speed, and the smaller value of the residual current passing through the residual current simulator can be stably increased to a rated direct current residual action current standard value within a certain time, so that a direct current residual current curve is obtained. The residual current simulation generation device can effectively test the performance of the residual current action protector of the direct current system, improve the product quality of the residual current action protector and further improve the safe and stable operation capability of the direct current system.

Drawings

Fig. 1 is a diagram of a residual current simulation generation apparatus provided in an embodiment of the present application;

fig. 2 is a diagram of a residual current simulation generation apparatus provided in an embodiment of the present application;

fig. 3 is a block diagram of a residual current simulator provided in an embodiment of the present application;

FIG. 4 is a graph of the DC smoothed residual current produced under no load conditions as provided in one embodiment of the present application;

FIG. 5 is a graph of a dc smoothed residual current with sudden onset under no load conditions as provided in one embodiment of the present application;

FIG. 6 is a graph of DC residual current with high frequency components generated under no-load conditions according to an embodiment of the present application;

FIG. 7 is a graph of DC residual current with rush current and high frequency components generated under no-load conditions as provided in an embodiment of the present application;

FIG. 8 is a graph of pulsating DC residual current in the form of square waves generated under a load condition as provided in one embodiment of the present application;

FIG. 9 is a graph of pulsating DC residual current in sinusoidal form generated under a load condition as provided in an embodiment of the present application;

fig. 10 is a diagram of a residual current operated protection system provided in an embodiment of the present application;

fig. 11 is a diagram of a residual current operated protection system according to an embodiment of the present application.

Description of the main element reference numerals

Residual current simulation generation device 10

DC converter 110

Residual current simulator 120

Second DC converter 121

Controller 122

Controlled current source 123

Switch 130

First gate switch 131

Second gate switch 132

First breaker 141

Second circuit breaker 142

Third breaker 143

DC feedback load 150

Voltage detection device 160

Current detection device 170

Residual current operated protection system 20

Dc residual current operated protector 210

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and those skilled in the art will be able to make similar modifications without departing from the spirit of the application and it is therefore not intended to be limited to the embodiments disclosed below.

It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In 2017, international standard IEC TS 63053 drafted by the International electrotechnical Commission, 2017 general requirements for residual current operated protective electric appliances for direct current systems, and provisions are mainly made on the characteristics and classification of residual current operated protective devices for direct current systems. But China does not have standards related to the residual current operated protector for the direct current system at present. Therefore, research on a polymorphic dc residual current simulation generating device capable of realizing a test of a residual current operated protector for a dc system is urgent.

Referring to fig. 1, an embodiment of the present application provides a residual current simulation generating device 10. The residual current simulation generating device 10 includes a dc converter 110, a residual current simulator 120, and a switch 130. The dc converter 110 is electrically connected to a municipal ac power source. The residual current simulator 120 is connected in parallel to both ends of the first dc converter 110. The switch 130 is electrically connected between the first dc converter 110 and the residual current simulator 120. When the switch 130 is closed, the residual current simulator 120 generates direct current residual currents with different waveforms.

The municipal ac power supply may be a 380V, 10KVA ac power supply. The DC converter 110 can be an AC 380V input, a DC 90V-400V output and a rated current 150A. The dc converter 110 can convert 380V ac power into 90V-400V dc power, and provide power for analog generation of dc residual current. The residual current simulator 120 is a current source with the output voltage of 0V-16V and the output current of 10 mA-10A. When the switch 130 is turned on, the residual current simulator 120 may be incorporated into one pole of the dc converter 110. The residual current simulator 120 may adjust the magnitude of the output current, so that the residual current simulation generating device 10 generates dc smoothed residual currents with different magnitudes. The different waveforms include square wave ripple waveforms, ripple waveforms in sinusoidal form, and waveforms with high frequency components.

In this embodiment, the residual current simulation generating device 10 includes a first dc converter 110, a residual current simulator 120 connected in parallel to two ends of the dc converter 110, and a switch 130 electrically connected between the dc converter 110 and the residual current simulator 120. After the switch 130 is closed, the dc converter 110 outputs a voltage, and the resistance of the residual current simulator 120 may stably change at a constant speed, so that a smaller value of the residual current passing through the residual current simulator 120 may be stably increased to a rated dc residual operating current standard value within a certain time, thereby obtaining a dc residual current curve. The residual current simulation generation device 10 can effectively test the performance of the residual current operated protector of the direct current system, improve the product quality of the residual current operated protector, and further improve the safe and stable operation capability of the direct current system.

Referring to fig. 2, in one embodiment, the residual current simulator 120 includes a second dc converter 121, a controller 122 and a controlled current source 123.

The second dc converter 121 is electrically connected to a municipal ac power supply. The controller 122 is electrically connected to the second dc converter 121. The controlled current source 123 is electrically connected to the second dc converter 121 and the controller 122, respectively. And the switch 130 is electrically connected between the first dc converter 110 and the controlled current source 123.

Specifically, referring to fig. 3, the controller 122 includes an acquisition card, a single chip, a network port, and a data storage. The controller 122 may collect output signals of the second dc converter 121 and the controlled current source 123 through the acquisition card, transmit the output signals to the single chip, and store the output signals in the data storage. The controller 122 performs information interaction with an external software platform through the internet access. The LabVIEW-based software platform of the controller 122 consists of a user interface program and a signal editing program. The form, the size and the frequency of the residual current are set through a LabVIEW-based software platform, and data are transmitted to the controlled current source 123 through the single chip microcomputer to be output.

In one embodiment, the switch 130 includes a first gate switch 131 and a second gate switch 132.

The first gating switch 131 is electrically connected between the first terminal of the controlled current source 123 and the first dc converter 110. The second gate switch 132 is electrically connected between the second terminal of the controlled current source 123 and the first dc converter 110.

The first gate switch 131 and the second gate switch 132 may have the same structure. Each gate switch comprises two switching tubes. When the residual current simulation generating device 10 operates, any one of the two switching tubes of the first gating switch 131 is turned on, and the corresponding switching tube of the two switching tubes of the second gating switch 132 is also turned on. For example, the first gate switch 131 includes a switching tube a and a switching tube b. The second gate switch 132 includes a switch tube c and a switch tube d. The output end of the dc converter 110 is a two-pole output. The switch tube a is electrically connected between a pole of the dc converter 110 and a first end of the controlled current source 123. The switch tube b is electrically connected between the other pole of the dc converter 110 and the first end of the controlled current source 123. The switch tube c is electrically connected between one pole of the dc converter 110 and the second end of the controlled current source 123. The switch tube d is electrically connected between the other pole of the dc converter 110 and the second end of the controlled current source 123. At this time, when the switching tube a and the switching tube d are closed and the switching tube b and the switching tube c are turned off, the controlled current source 123 may be incorporated into one pole of the dc converter 110. The controlled current source 123 may adjust its output current, so that the residual current simulation generating device 10 generates different levels of dc smoothed residual currents. When the switching tube b and the switching tube c are closed and the switching tube a and the switching tube d are turned off, the controlled current source 123 may be incorporated into the other pole of the dc converter 110. The controlled current source 123 may adjust its output current, so that the residual current simulation generating device 10 generates different levels of dc smoothed residual currents.

In one embodiment, the residual current simulation generating device 10 further includes a first breaker 141.

The first circuit breaker 141 is electrically connected between the second dc converter 121 and a municipal ac power supply. When the first circuit breaker 141 is turned on, the switching tube a and the switching tube d are closed, and the output voltage of the second dc converter 121 is adjusted according to a preset condition, so that the controlled current source 123 generates a corresponding dc residual current, and thus a dc residual current with a positive polarity can be obtained under an idle condition. And opening the first circuit breaker 141, closing the switching tube b and the switching tube c, turning on the first circuit breaker 141, and adjusting the output voltage of the second dc converter 121 according to a preset condition, so that the controlled current source 123 generates a corresponding dc residual current, thereby obtaining a smooth residual current with a negative polarity under no-load condition.

The dc smoothed residual current produced under no load conditions resulting from the above method is shown in fig. 4. With the residual current simulator 120, at 5s, one pole in the loop starts to generate residual current, which increases smoothly with time, and at 35s, the residual current increases to I_△nThen the residual current remains as I_△nUp to 40 s. The current of the other pole is always zero.

The sudden appearance of the dc smoothed residual current under no load conditions resulting from the above method is shown in fig. 5. With the residual current simulator 120, a pole in the 10s loop is generated with a magnitude of I_△nThe residual current of (3) is maintained to 40 s. The current of the other pole is always zero.

The dc residual current with high frequency components generated under no-load conditions obtained by the above method is shown in fig. 6. With the residual current simulator 120, a pole in the 10s loop is generated with a magnitude of I_△nThe residual current of nearby oscillations, remained to 40 s. The current of the other pole is always zero.

The method can generate high impulse current under no-load conditionThe dc residual current of the frequency components is shown in fig. 7. With the residual current simulator 120, at the 10 th s, one pole in the loop generates 2I_△nThen the residual current is at I_△nNearby oscillations, kept to 40 s. The current of the other pole is always zero.

In one embodiment, the residual current simulation generating device 10 further includes a dc feedback load 150, a second circuit breaker 142, and a third circuit breaker 143. The dc feedback load 150 is connected to the first dc converter 110 to form a dc main circuit. The voltage grade of the direct current main loop is 90-400V, and the current grade is 0-150A. The second circuit breaker 142 is electrically connected between the first end of the dc feedback load 150 and the first dc converter 110. The third circuit breaker 143 is electrically connected between the second end of the dc feedback load 150 and the first dc converter 110. The direct current feedback load 150 is direct current input of 90V-400V, rated current of 150A and power of 60 kW.

When the first breaker 141, the second breaker 142 and the third breaker 143 are all turned on, the switch tube a and the switch tube d are closed, a constant voltage of 0V to 400V is set to be output by the first dc converter 110, and the output current is set to be I_n(rated Current value, I)_n) The output voltage of the second dc converter 121 is adjusted according to a preset condition, so that the controlled current source 123 generates a corresponding dc residual current, and thus a dc residual current with positive polarity under a load condition can be obtained. Opening the first breaker 141, closing the switch tube b and the switch tube c, turning on the first breaker 141, setting the first dc converter 110 to output a constant voltage of 0V-400V, and setting the output current to be set I_n(rated Current value, I)_n) The output voltage of the second dc converter 121 is adjusted according to a preset condition, so that the controlled current source 123 generates a corresponding dc residual current, and thus a dc residual current with a negative polarity under a load condition can be obtained.

Pulsating DC remnant in the form of a square wave generated under load conditions obtained by the above methodThe current is shown in fig. 8. The frequency is 100 Hz. With the residual current simulator 120, one pole in the loop is at I in 10ms_n(rated Current value, I)_n) On the basis of the generation of a size I_△nAt 15ms, the residual current is reduced to zero, and the current is I_nHold for 5ms, and then repeat the process. The current of the other pole is always I_nAnd the directions are opposite.

The sinusoidal pulsating dc residual current generated under load conditions resulting from the above method is shown in fig. 9. The frequency is 100 Hz. With the residual current simulator 120, one pole in the loop is at I in 10ms_n(rated Current value, I)_n) On the basis of the generation of a size I_△nThe residual current is reduced to zero in 15ms, and the current is I_nHold for 5ms, and then repeat the process. The current of the other pole is always I_nAnd the directions are opposite.

The residual current simulation generation device 10 utilizes the residual current simulator 120 to generate complex and accurate direct current residual currents with different forms, sizes and frequencies according to preset control conditions, so as to simulate real residual current working conditions, particularly residual currents containing impact currents and high-frequency components, appearing in a direct current system, further realize the test of residual current action protectors for the direct current systems with different action values and different bandwidths, the residual current simulation generation device 10 can adjust the polarity of the residual currents, the residual current simulator 120 is positioned at the positive pole and the negative pole of a circuit to generate residual currents with different polarities by adjusting a gating switch, and the test of the residual current action protectors with the polarities for the direct current systems is realized.

In one embodiment, the residual current simulation generating device 10 further includes a voltage detecting device 160 and a current detecting device 170. The voltage detection device 160 is electrically connected to two ends of the first dc-dc converter 110, and is configured to detect an output voltage of the first dc-dc converter 110. The current detection device 170 is electrically connected between the second end of the controlled current source 123 and the second gating switch 132. In one alternative embodiment, the voltage detection device 160 is a voltage sensor, and the current detection device 170 is a hall current sensor. The voltage detection device 160 and the current detection device 170 can accurately detect the output voltage of the dc output converter 110 and the current passing through the residual current simulator 120 in real time, thereby ensuring high accuracy of the generated residual current.

Referring to fig. 10, an embodiment of the present application provides a residual current operated protection system 20. The residual current operated protection system 20 comprises the residual current simulation generating device 10 and the direct current residual current operated protector 210 according to any one of the above embodiments. The dc residual current operated protector 210 is electrically connected to the residual current simulation generating device 10.

Specifically, referring to fig. 11, the dc residual current device 210 is electrically connected between the dc converter 110 and the dc feedback load 150. When the residual current passing through the dc residual current operated protector 210 exceeds the operation threshold, the dc residual current operated protector 210 cuts off the loop for protection. A fourth circuit breaker may be provided between the dc residual current device 210 and the dc converter 110. A plurality of current electrical measuring devices may be provided throughout the residual current operated protection system 20. For example, a current detection device may be respectively disposed at two output terminals of the dc converter 110, so as to detect the current on each branch.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.