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 王静 赵宇明 李艳 陈思磊 谢智敏 于 2019-09-24 设计创作，主要内容包括：本申请涉及一种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,包括直流变换器、并联于所述直流变换器两端的直流变阻器以及电连接于所述直流变换器与所述直流变阻器之间的开关器。当所述开关器闭合后,直流变换器输出电压,并且所述直流变阻器的阻值可以匀速稳定变化,在一定时间内,可以使通过所述直流变阻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 direct current converter, a direct current rheostat connected in parallel to two ends of the direct current converter and a switch electrically connected between the direct current converter and the direct current rheostat. When the switch is closed, the direct current converter outputs voltage, the resistance value of the direct current rheostat can be changed stably at a constant speed, and the smaller value of the residual current passing through the direct current rheostat can be stably increased to the 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 DC converter (110) electrically connected to a municipal AC power supply;

a DC rheostat (120) connected in parallel to both ends of the DC converter (110); and

and the switch (130) is electrically connected between the direct current converter (110) and the direct current rheostat (120), and when the switch (130) is closed, direct current residual current is generated through the direct current rheostat (120).

2. The residual current simulation generating device according to claim 1, wherein the switch (130) comprises:

a first gate switch (131) electrically connected between a first end of the dc varistor (120) and the dc converter (110); and

and the second gating switch (132) is electrically connected between the second end of the direct current rheostat (120) and the direct current converter (110).

3. The residual current simulation generation apparatus according to claim 2, further comprising:

and the first breaker (141) is electrically connected between the second end of the direct current rheostat (120) and the second gating switch (132).

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

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

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

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

and the third breaker (143) is electrically connected between the second end of the direct current feedback load (150) and the direct current converter (110).

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

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

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

and the current detection device (170) is electrically connected between the second end of the direct current rheostat (120) and the second gating switch (132).

8. The residual current simulation generating device according to claim 7, wherein the voltage detecting device (160) is a voltage sensor and the current detecting device (170) is a Hall current sensor.

9. The residual current simulation generation device according to claim 8, wherein the input voltage of the dc converter (110) is ac 380V, the output voltage of the dc converter (110) is dc 90V to 400V, and the rated current of the dc converter (110) is 150A.

10. The residual current analog generation device according to any one of claims 1 to 9, characterized in that the dc rheostat (120) is a digital programmable rheostat, the adjustment current step size being 0.01 mA.

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

the direct current rheostat is connected in parallel with two ends of the direct current converter; and

and the switch is electrically connected between the direct current converter and the direct current rheostat, and when the switch is closed, direct current residual current is generated through the direct current rheostat.

In one embodiment, the switch comprises:

the first gating switch is electrically connected between the first end of the direct current rheostat and the direct current converter; and

and the second gating switch is electrically connected between the second end of the direct current rheostat and the direct current converter.

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

and the first breaker is electrically connected between the second end of the direct current rheostat and the second gating switch.

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

and the direct current feedback load is connected with the 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 direct current converter; and

and the third circuit breaker is electrically connected between the second end of the direct current feedback load and the 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 direct current converter and used for detecting the output voltage of the 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 direct current rheostat 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 direct current converter is 380V alternating current, the output voltage of the direct current converter is 90V to 400V direct current, and the rated current of the direct current converter is 150A.

In one embodiment, the direct current rheostat is a digital programmable rheostat, and the step size of the adjusting current is 0.01 mA.

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 direct current converter, a direct current rheostat connected in parallel to two ends of the direct current converter and a switch electrically connected between the direct current converter and the direct current rheostat. When the switch is closed, the direct current converter outputs voltage, the resistance value of the direct current rheostat can be changed stably at a constant speed, and the smaller value of the residual current passing through the direct current rheostat can be stably increased to the 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 graph of DC residual current produced under no-load conditions as provided in an embodiment of the present application;

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

FIG. 5 is a graph of DC residual current produced under a load condition as provided in an embodiment of the present application;

FIG. 6 is a graph of a sudden DC residual current generated under a load condition as provided in an embodiment of the present application;

fig. 7 is a diagram of a residual current operated protection system provided in an embodiment of the present application;

fig. 8 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

DC rheostat 120

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 smooth 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 dc varistor 120, and a switch 130. The dc converter 110 is electrically connected to a municipal ac power source. The dc varistor 120 is connected in parallel to both ends of the dc converter 110. The switch 130 is electrically connected between the dc converter 110 and the dc varistor 120, and when the switch 130 is closed, a dc residual current is generated by the dc varistor 120.

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 dc rheostat 120 may be a high-precision digital programmable rheostat, and the current step is adjusted to 0.01 mA. When the switch 130 is turned on, the dc varistor 120 may be incorporated into one pole of the dc converter 110. The dc varistor 120 may adjust its own resistance value, so that the residual current simulation generating device 10 may generate dc smoothed residual currents with different magnitudes.

In this embodiment, the residual current simulation generating device 10 includes a dc converter 110, a dc varistor 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 dc varistor 120. After the switch 130 is closed, the dc converter 110 outputs a voltage, and the resistance of the dc rheostat 120 can be changed stably at a constant speed, so that a smaller value of the residual current passing through the dc rheostat 120 can 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 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 end of the dc varistor 120 and the dc converter 110. The second gating switch 132 is electrically connected between the second end of the dc varistor 120 and the 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 one pole of the dc converter 110 and one end of the dc varistor 120. The switching tube b is electrically connected between the other pole of the dc converter 110 and one end of the dc varistor 120. The switch tube c is electrically connected between one pole of the dc converter 110 and the other end of the dc varistor 120. The switch tube d is electrically connected between the other pole of the dc converter 110 and the other end of the dc varistor 120. 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 dc varistor 120 may be incorporated into one pole of the dc converter 110. The dc varistor 120 may adjust its own resistance value, so that the residual current simulation generating device 10 may generate dc smoothed residual currents with different magnitudes. 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 dc varistor 120 may be incorporated into the other pole of the dc converter 110. The dc varistor 120 may adjust its own resistance value, so that the residual current simulation generating device 10 may generate dc smoothed residual currents with different magnitudes.

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 end of the dc varistor 120 and the second gating switch 132. When the first breaker 141 is turned on, the switching tube a and the switching tube d are closed, the output voltage of the dc converter 110 is set, and the output resistance of the dc varistor 120 is adjusted so that the generated dc smooth residual current is never greater than 0.2I_△n(I_△nRated direct current residual motionAs a current standard value) starts to increase steadily, reaching I within 30s_△nThe value can obtain the direct current smoothing residual current with positive polarity under the no-load condition. The resulting dc smoothed residual current under no load conditions is shown in fig. 3. At 5s, one pole in the loop starts to generate a 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. Opening the first breaker 141, resetting the dc varistor 120, turning on the first breaker 141, closing the switching tube b and the switching tube c, setting the output voltage of the dc converter 110, and adjusting the dc varistor 120 to generate a dc smoothed residual current no greater than 0.2I_△n(I_△nRated dc residual operating current standard value) starts to increase steadily and reaches I within 30s_△nThe value can obtain the DC smoothing residual current with negative polarity under no-load condition.

When the switching tube a and the switching tube d are closed, the output voltage of the dc converter 110 is set, the output resistance of the dc varistor 120 is adjusted, and the preset value of the residual current is adjusted, then the first circuit breaker 141 is closed, so that the direct current smooth residual current with positive polarity suddenly appearing under the no-load condition can be obtained. The resulting sudden appearance of a dc smoothed residual current under no load conditions is shown in fig. 4. One pole generation in the 10s loop is of size I_△nThe residual current of (3) is maintained to 40 s. The current of the other pole is always zero. The first breaker 141 is opened, the switch tube b and the switch tube c are closed, the output voltage of the dc converter 110 is set, the dc varistor 120 is adjusted, and after the preset value of the residual current is adjusted, the first breaker 141 is closed, so that the negative dc smooth residual current suddenly appearing under the no-load condition can be obtained.

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 dc converter 110 to form a dc main loop. 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 dc converter 110. The third circuit breaker 143 is electrically connected between the second end of the dc feedback load 150 and the 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 switching tube a and the switching tube d are closed, the output voltage of the dc converter 110 is set, and the dc varistor 120 is adjusted to generate a dc smoothed residual current no greater than 0.2I_△n(I_△nRated dc residual operating current standard value) starts to increase steadily and reaches I within 30s_△nThe value can obtain the direct current smoothing residual current with positive polarity under the load condition. The resulting dc smoothed residual current under load conditions is shown in fig. 5. At 5s, one pole in the loop is at I_n(rated Current value, I)_n) On the basis of that, the residual current is generated from zero, the residual current is smoothly increased along with the time, and at the 35 th s, the residual current is increased to I_△nThen the residual current remains as I_△nUp to 40 s. The current of the other pole is always I_nAnd in the opposite direction to the other pole. Opening the first breaker 141, resetting the dc varistor 120, turning on the first breaker 141, closing the switching tube b and the switching tube c, setting the output voltage of the dc converter 110, and adjusting the dc varistor 120 to generate a dc smoothed residual current no greater than 0.2I_△n(I_△nRated dc residual operating current standard value) starts to increase steadily and reaches I within 30s_△nThe value can obtain the DC smoothing residual current with negative polarity under the load condition.

When the second breaker 142 and the third breaker 143 are both turned on, the switching tube a and the switching tube d are closed, the output voltage of the dc converter 110 is set,after the dc varistor 120 is adjusted and the preset value of the residual current is adjusted, the first circuit breaker 141 is closed, so that the positive-polarity dc smoothed residual current suddenly appearing under the load condition can be obtained. The resulting sudden appearance of a dc smoothed residual current under no load conditions is shown in fig. 6. At 10s, one pole in the loop generates a magnitude of I_△nThe residual current of (3) is maintained to 40 s. The current of the other pole is always I_nAnd in the opposite direction to the other pole. The first breaker 141 is opened, the switch tube b and the switch tube c are closed, the output voltage of the dc converter 110 is set, the dc varistor 120 is adjusted, and after the preset value of the residual current is adjusted, the first breaker 141 is closed, so that the negative dc smoothed residual current suddenly appearing under the load condition can be obtained.

The residual current simulation generation device 10 can generate different resistance values according to preset control conditions by using the high-precision digital programmable rheostat, so that the device can generate direct current smooth residual currents with different sizes, and tests of residual current action protectors for direct current systems with different action values are realized. The polarity of the residual current generated by the residual current simulation generating device 10 is adjustable, and the dc rheostat 120 is positioned at the positive electrode and the negative electrode of the circuit by adjusting the gating switch to generate residual currents with different polarities, so as to realize the test of the polar residual current operated protector for the dc system.

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 dc converter 110, and is configured to detect an output voltage of the dc converter 110. The current detecting device 170 is electrically connected between the second end of the dc varistor 120 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 dc rheostat 120 in real time, thereby ensuring high accuracy of the generated residual current.

Referring to fig. 7, 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. 8, 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.