CN102377156B - Ground detection protective device for electric power comprehensive test vehicle - Google Patents

Abstract

The invention discloses a grounding detection and protection device for a comprehensive electric power test vehicle, which includes a hardware simulation detection control module for receiving impedance signals of conductive tire grounding and vehicle frame direct grounding, and the hardware simulation detection control module is connected to control a An electric execution circuit, the power-on execution circuit is also connected and controlled by a software digital detection control module, the software digital detection control module is connected to the hardware analog detection control module, and the software digital detection control module is used to collect The hardware simulation detects the intermediate information of the control module. The ground detection and protection device can detect the slight difference in grounding impedance between the conductive tire grounding and the direct grounding grounding of the vehicle frame, thereby effectively judging whether the grounding is reliable or not.

Description

Grounding detection and protection device for comprehensive electric power test vehicle

technical field

The invention relates to the technical field of high-voltage electric equipment testing, in particular to a grounding detection and protection device for a comprehensive electric power test vehicle.

Background technique

The electric power comprehensive test vehicle is a vehicle-mounted intensive computer-controlled test system. The vehicle is used as the carrier. The test system is installed in the vehicle with a building block structure, and the test work is completed by computer control.

For example, the test systems of the above-mentioned vehicle-mounted instruments are all high-voltage test instruments, so reliable grounding is the primary task to ensure personal safety and the smooth completion of test work.

At present, in the test work of the test system in the electric comprehensive test vehicle, it is mainly grounded artificially. This grounding method cannot avoid the loss of life and property caused by human negligence.

The tires of the original electric comprehensive test vehicle are insulating tires, which can easily detect whether the ground is grounded or not. However, in order to discharge the static electricity generated by the vehicle during operation to the ground, the tires of the existing electric comprehensive test vehicle are changed to conductive tires. , which is an improvement in itself, but in the test work of electric power equipment, the grounding of the conductive tire does not meet the strict requirements of the ground protection regulations in the electric power test. And the grounding of the conductive tire and the frame are directly grounded, and there is only a slight difference in the grounding impedance. Judging from the magnitude of the ground impedance converted into a voltage signal, the existing measures have been unable to distinguish whether it is close to a safe ground.

Contents of the invention

In order to overcome the deficiencies in the prior art, the purpose of the present invention is to provide a ground detection and protection device for a comprehensive electric power test vehicle, which can detect the small difference in the impedance of the grounding of the conductive tire and the direct grounding of the vehicle frame, thereby effectively The judgment is reliable grounding.

In order to solve the above-mentioned technical problems and achieve the above-mentioned technical purpose, the present invention adopts the following technical solutions:

A grounding detection and protection device for a comprehensive electric power test vehicle, which includes a hardware simulation detection control module for receiving impedance signals of conductive tire grounding and vehicle frame direct grounding, the hardware simulation detection control module is connected to control a power-on execution circuit, The power-on execution circuit is also connected and controlled by a software digital detection control module, the software digital detection control module is connected to the hardware analog detection control module, and the software digital detection control module is used to collect the hardware analog detection control module. Check the intermediate information of the control module.

Preferably, the software digital detection control module is also connected to a host computer, and the host computer is used for man-machine communication.

Further, the hardware analog detection control module includes: an input impedance photoelectric isolation sampling circuit for calculating the difference between the impedance of the conductive tire grounding and the direct grounding of the vehicle frame; The exponential operation signal expansion circuit for nonlinear amplification, a signal-pulse width automatic conversion circuit for converting the amplified impedance difference signal into pulse width, and a signal filter comparison circuit for realizing signal filtering and comparison functions, The input impedance photoelectric isolation sampling circuit is connected to the exponential operation signal expansion circuit, the exponential operation signal expansion circuit is connected to the signal-pulse width automatic conversion circuit, and the signal-pulse width automatic conversion circuit is connected to the signal filtering comparison circuit, the signal filtering and comparing circuit is connected to the power-on execution circuit.

Further, the software digital detection control module is a fuzzy operation automatic control system based on a single-chip microcomputer system. The single-chip microcomputer system is provided with a signal sampling port connected to the input impedance photoelectric isolation sampling circuit, and a signal sampling port connected to the input impedance photoelectric isolation sampling circuit. The exponential operation port behind the exponent operation signal expansion circuit, a pulse width sampling port connected to the signal-pulse width automatic conversion circuit and a fuzzy operation control port for connecting with the power-on execution circuit, the signal Sampling, exponential operation, pulse width sampling and fuzzy operation control are completed through the internal program of the single-chip microcomputer system.

Preferably, the single-chip microcomputer system is connected with a sound and light alarm module, and the sound and light alarm module is used to remind the operator when the instrument is detected to be poorly grounded, and notify the single-chip microcomputer system to cut off the power supply of all instruments to prevent grounding bad and cause accidents.

Preferably, the single-chip microcomputer system is connected to an LED instrument operation indicator module, and the LED instrument operation indicator module is used to indicate the instrument in operation, which is convenient for operators to understand intuitively.

Working process of the present invention is as follows:

1) System startup initialization;

2) Sampling the input signal, including the grounding impedance of the conductive tire and the direct grounding impedance of the vehicle frame;

3) Perform signal index calculation;

4) Determine whether the obtained result is less than the set value? If not, power off the instrument, sound and light alarm at the same time, and notify the host computer for man-machine communication; if yes, sample the pulse width signal;

5) Determine whether the obtained pulse width signal is greater than the set value? If not, power off the instrument, sound and light alarm at the same time, and notify the upper computer for human-machine communication; The light module section provides an intuitive view of the instrument being run.

The grounding detection and protection device of the electric power comprehensive test vehicle of the present invention adopts a hardware operation automatic control circuit (hardware analog detection control module) and a single chip microcomputer software fuzzy operation automatic control (double scheme of software digital detection control module), and can accurately judge vehicle conductive tires The function of the grounding impedance of the grounding and the direct grounding of the frame is slightly different, so as to correctly judge whether the instrument is reliably grounded.

Description of drawings

Fig. 1 is a functional block diagram of the present invention.

Fig. 2 is a connection schematic diagram of a specific embodiment of the present invention.

FIG. 3 is a circuit diagram of an exponential operation signal expansion circuit according to an embodiment of the present invention.

Fig. 4 is a circuit diagram of a pulse width generating circuit according to an embodiment of the invention.

FIG. 5 is an output waveform diagram of an exponential amplifier according to an embodiment of the present invention.

Explanation of symbols in the figure: 1. Hardware analog detection control module, 2. Power-on execution circuit, 3. Software digital detection control module, 4. Host computer, 5. Sound and light alarm module, 6. LED instrument operation indicator module, 101. Input impedance photoelectric isolation sampling circuit, 102. Exponential operation signal expansion circuit, 103. Signal-pulse width automatic conversion circuit, 104. Signal filter comparison circuit, 301. Signal sampling, 302. Exponential operation, 303. Pulse width sampling, 304. Single-chip microcomputer system, 305. Fuzzy operation control.

Detailed ways

Please refer to Fig. 1 and Fig. 2, a kind of electric comprehensive test car ground detection and protection device, which includes a hardware simulation detection control module 1 for receiving the impedance signal of conductive tire grounding and vehicle frame direct grounding, the hardware simulation The detection control module 1 is connected to control a power-on execution circuit 2, and the power-on execution circuit 2 is also connected and controlled by a software digital detection control module 3, the software digital detection control module 3 and the hardware analog detection control module 1 connected to each other, the software digital detection control module 3 is used to collect the intermediate information of the hardware analog detection control module 1 .

Preferably, the software digital detection control module 3 is also connected with a host computer 4, and the host computer 4 is used for man-machine communication.

Further, the hardware analog detection control module 1 includes: an input impedance photoelectric isolation sampling circuit 101 for calculating the difference between the impedance of the conductive tire grounding and the direct grounding of the vehicle frame; Exponential operation signal expansion circuit 102 for exponential nonlinear amplification, a signal-pulse width automatic conversion circuit 103 for converting the amplified impedance difference signal into pulse width, and a signal for realizing signal filtering and comparison functions Filter comparison circuit 104, the input impedance photoelectric isolation sampling circuit 101 is connected to the exponential operation signal expansion circuit 102, and the exponential operation signal expansion circuit 102 is connected to the signal-pulse width automatic conversion circuit 103, and the signal-pulse width The automatic conversion circuit 103 is connected to the signal filter comparison circuit 104 , and the signal filter comparison circuit 104 is connected to the power-on execution circuit 2 .

Further, the software digital detection control module 3 is a fuzzy operation automatic control system based on the single-chip microcomputer system 304. The single-chip microcomputer system 304 is provided with a signal sampling port 301 connected to the input impedance photoelectric isolation sampling circuit 101. , one is connected to the exponential operation 302 port after the exponential operation signal expansion circuit 102, one is connected to the pulse width sampling 303 port after the signal-pulse width automatic conversion circuit 103, and one is used to connect with the power-on execution circuit 2 The fuzzy operation control port 305, the signal sampling 301, exponential operation 302, pulse width sampling 303 and fuzzy operation control 305 are completed by the internal program of the single-chip microcomputer system 304.

Preferably, the single-chip microcomputer system 304 is connected with a sound and light alarm module 5, and the sound and light alarm module 5 is used to remind the operator when detecting poor grounding of the instrument, and notify the single-chip microcomputer system 304 to cut off all instrument power supplies , to prevent accidents caused by poor grounding.

Preferably, the single-chip microcomputer system 304 is connected with an LED instrument operation indicator module 6, and the LED instrument operation indicator module 6 is used to indicate the instrument in operation, which is convenient for operators to understand intuitively.

As shown in Figure 3, it is an exponent operation signal expansion circuit diagram of an embodiment of the present invention. It selects a low-drift, low-noise, high-impedance input operational amplifier, and selects a triode "pair tube" to offset the drift caused by temperature. . Its output form can be proved as:

$\mathrm{<span\; class="notranslate">\; VO</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; Rf</span>}}{\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; Vre</span>}{\mathrm{<span\; class="notranslate">\; 10</span>}}^{<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; Vi</span>}}{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}}$

Where Vi = input signal; Vre = reference voltage; τ = constant.

The output of the exponential operation signal expansion circuit is a modified half-sine wave, as shown in Figure 5, which shows the original waveform of the vehicle conductive tire grounded and the frame directly grounded and the output waveform of the exponential nonlinear amplifier circuit. As can be seen from Fig. 5, two kinds of situations, through the exponential nonlinear amplification, their amplitude and the bottom have differed a lot, as shown in Fig. 4, it is the pulse width generating circuit of an embodiment of the present invention, essentially it It is a comparator circuit. When the frame is directly grounded, the preset variable resistor W2 makes the pulse width 2.5mS, and it is about 1mS when the electric tire is grounded. After passing through the comparator, pulses with different widths are obtained. Since the pulse width is already very different, it can be simply filtered and integrated, and after comparison, it can accurately determine whether the grounding of the vehicle's conductive tire or the direct grounding of the frame is used to control the power-on relay and supply power to the instrument.

The above are only specific application examples of the present invention, and do not constitute any limitation to the protection scope of the present invention. Any technical solution formed by equivalent transformation or equivalent replacement, or any detection method for the grounding of the conductive tire of the vehicle and the direct grounding of the frame of the vehicle described in the present invention, all fall within the protection scope of the present invention.

Claims (5)

1. a ground detection protective device for electric power comprehensive test vehicle, it is characterized in that, comprise: one for receiving the hardware simulation detection control module (1) of conductive tyre ground connection and the directly grounded impedance signal of vehicle frame, described hardware simulation detection control module (1) connection control one powers on executive circuit (2), the described executive circuit that powers on (2) also connects and is controlled by a software digital detection control module (3), and described software digital detection control module (3) and described hardware simulation detection control module (1) are interconnected; Described software digital detection control module (3) is for gathering the average information of described hardware simulation detection control module (1); described hardware simulation detection control module (1) comprising: one for completing the input impedance Phototube Coupling sample circuit (101) of the mathematic interpolation of conductive tyre ground connection and the directly grounded impedance of vehicle frame, one for completing the exponent arithmetic signal expansion circuit (102) described impedance differences being carried out index Image magnify, one converts the signal-pulse duration automatic switching circuit (103) and of pulse duration to for realizing the signal filtering comparison circuit (104) of signal filtering and comparing function for completing the impedance differences signal after by amplification, described input impedance Phototube Coupling sample circuit (101) connects described exponent arithmetic signal expansion circuit (102), described exponent arithmetic signal expansion circuit (102) connects described signal-pulse duration automatic switching circuit (103), described signal-pulse duration automatic switching circuit (103) connects described signal filtering comparison circuit (104), power on described in described signal filtering comparison circuit (104) connects executive circuit (2).

2. ground detection protective device for electric power comprehensive test vehicle according to claim 1, it is characterized in that, described software digital detection control module (3) is one based on the fuzzy operation automatic control system of Single Chip Microcomputer (SCM) system (304), described Single Chip Microcomputer (SCM) system (304) is provided with, one is connected to signal sampling (301) port after described input impedance Phototube Coupling sample circuit (101), one is connected to exponent arithmetic (302) port after described exponent arithmetic signal expansion circuit (102), one be connected to signal-pulse duration automatic switching circuit (103) after pulse-width samples (303) port and control (305) port for the fuzzy operation be connected with the described executive circuit that powers on (2), described signal sampling (301), exponent arithmetic (302), pulse-width samples (303) and fuzzy operation are controlled (305) and are completed by the program that described Single Chip Microcomputer (SCM) system (304) is inner.

3. ground detection protective device for electric power comprehensive test vehicle according to claim 1 and 2; it is characterized in that; described software digital detection control module (3) is also connected with a host computer (4), and described host computer (4) is for carrying out man-machine communication.

4. ground detection protective device for electric power comprehensive test vehicle according to claim 2; it is characterized in that; described Single Chip Microcomputer (SCM) system (304) connects, light alarm module (5); described sound, light alarm module (5) are for when detecting that instrument ground is bad; remind operating personnel; and notify that described Single Chip Microcomputer (SCM) system (304) cuts off all appts power supply, prevent from causing the accident because of imperfect earth.

5. ground detection protective device for electric power comprehensive test vehicle according to claim 2; it is characterized in that; described Single Chip Microcomputer (SCM) system (304) connects LED instrument run indicator module (6); described LED instrument run indicator module (6) is used to indicate the instrument run, and convenient operation personnel get information about.