JPH0339660A - Three-phase voltage detecting device for high-voltage equipment - Google Patents

Abstract

PURPOSE:To enable three-phase voltage detection by one voltage detecting amplifier by superposing a voltage, obtained by inverting the phase of a voltage induced at a voltage detection electrode nearby a conductor of one phase, upon voltages induced at electrodes nearby conductors of other two phases. CONSTITUTION:This device detect the voltage of the high-voltage equipment where a three-phase current flows. Here, the voltage detection electrodes 4 - 6 are provided nearby the conductors 1 - 3 of the respective phases of the high-voltage equipment. Then an inverting amplifier 7 is connected to the electrode 4 arranged nearby the conductor 1 of one specific phase, its induced voltage is inverted in phase and superposed upon the voltages induced at the electrodes 5 and 6 arranged nearby the conductors 2 and 3 of other two phases, and the resulting voltage is inputted to the voltage detecting amplifier 8. Here, a rectified voltage is compared with a specific st voltage to decide whether or not there is the voltage of the high-voltage equipment.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Application The present invention relates to a three-phase voltage detection device for high 1u voltage equipment, which performs voltage detection on high voltage equipment such as a switch 4.

B3 Summary of the Invention The present invention provides a three-phase voltage detection device for high-voltage equipment that performs voltage detection on high-71-voltage equipment through which three-phase current flows. Of these, the phase-inverted induced voltage of the fri pole placed close to the negative phase conductor is superimposed with the induced voltage of each M pole placed close to the other two phase conductors, and the superimposed 1ri By introducing voltage into the voltage detection amplifier and determining the presence or absence of voltage, three-phase voltage detection can be performed using a single voltage detection amplifier, which has been conventionally used.

C1 High II of conventional technology switches, etc.! In pressure equipment, voltage detection is performed to confirm safe work through three-phase no-pressure detection and to serve as an electrical interlock.

Conventionally, voltage detection for high-voltage machines with three-phase currents involves placing a voltage detection electrode facing a high-voltage part such as a conductor, capturing the voltage generated in the electrode due to electrostatic induction, and detecting the presence of the voltage. I was judging F11.

D1 Problem to be Solved by the Invention Therefore, in order to determine the presence or absence of voltage in all phases of a device through which three-phase current flows by the method described above, it is necessary to
I had to install 1HW and 71 voltage detection amplifiers. Therefore, carrying out three-phase voltage detection requires three times the cost and three times the space as negative phase voltage detection. Due to the above-mentioned principle and the fact that open phase JJt failures are rare, the current situation is that only one of the three phases is detected.

The present invention has been made in view of the above points, and its purpose is to:
Enables three-phase voltage detection with one voltage detection amplifier,
Our objective is to provide a three-phase voltage detection device for high-voltage equipment that reduces costs.

E,l'! Means for Solving 11m The present invention provides a three-phase voltage detection device for high-voltage equipment that performs the detection of a high-voltage machine Z (high 71-voltage machine Z) in which a three-phase TLT flow flows, in which each phase conductor of the high-voltage equipment is an inverting amplifier that inverts the phase of the induced voltage of the voltage sensing electrode installed near the conductor of a predetermined one phase of the voltage sensing electrodes, and the other two phases of the voltage sensing electrodes. An AC voltage obtained by superimposing the induced voltage of each voltage detecting electrode placed close to the conductor and the output voltage of the inverting amplifier is input, and the voltage obtained by rectifying the AC input voltage is compared with a predetermined set voltage. It is characterized by being equipped with a voltage detection amplifier that determines the presence or absence of voltage in high II! voltage equipment.

11. The phase of the voltage induced in the voltage detecting electrode placed close to the conductor of one phase of the high voltage allQ is reversed in phase by 180° by the inverting amplifier. Each test ffi? installed close to the other two-phase conductors of the high voltage equipment? [! II which synthesized the induced pressure of the pole! The phase of the voltage is the same as the output voltage phase of the inverting amplifier. Therefore, when a voltage is present in the high voltage equipment, a heavy pressure approximately twice as large as the m pressure induced from the -phase conductor is input to the voltage detection amplifier. In addition, when the number of high-voltage devices is out of phase, the input voltage of the voltage detection amplifier becomes smaller than the heavy pressure (which is approximately twice as large as above).

Furthermore, the heavy pressure iut L of high voltage equipment, and sometimes the input heavy pressure of the voltage detection amplifier, disappears. In this way, the magnitude of the input pressure is different when the high-voltage equipment is on and off (or when there is an open phase), so the three-phase detection 7I! can be performed with one voltage detection [t amplifier].

G. Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In Figure 1, l is Takaso pressure FM? , 4 are A-phase main circuit conductors, 2 is a B-phase production circuit conductor, and 3 is a C-phase main circuit conductor. 4,5. G is a detection fr1 electrode of each phase arranged opposite to the conductor 1°2.3 of each phase. 7 is the phase of the voltage induced from the human phase main circuit conductor 1 to the A phase detection m electrode 4.
It is an inverting amplifier that inverts by 0°. 8 is B phase examination mff1
This is a voltage detection amplifier into which voltages induced in f85 and C phase detection t'ut pole 6, respectively, and the output voltage of inverting amplifier 7 are input. This voltage detection amplifier 8 detects the presence (lit) of input voltage by making a level judgment, and is configured as shown in FIG. 2, for example. I! of the DC fIt source I3, which is rectified by the rectified voltage and set to a predetermined pressure.
! The pressure is compared by a comparator 14. The output of the comparator 14 is supplied to the transistor 17 via the resistors 15 and 16. For example, when the rectified output load is higher than the voltage of the DC power supply 13, the output of the comparator 14 becomes a positive level, and the transistor 17 It is controlled to be on, and as a result, a current flows to the relay coil 19 via the resistor I8, and a relay output is generated as an external output signal.

Further, when the rectified output 11t pressure is smaller than the pressure of the DC 1 source 13, the output of the comparator 14 becomes a negative level, the transistor 17 is turned off, and the relay coil 19 becomes de-energized. No output signal is generated.

In the apparatus configured as described above, a high 11t pressure 4i
! When there is 1a pressure in 1 unit, each phase detection ff1fff pole 4,
Voltage detection 1 induced by 5.6! ■The pressure vector is a in Figure 3.

They are shown as b, c. Among the voltage detection voltages, A phase detection v
1 induced by single pole 4! Since the phase of the voltage a is inverted by 180 degrees by the inverting amplifier 7, the voltage vectors of the output pressure a' of the inverting amplifier 7 and the voltage vectors of the B and C phase detectors 16-1 and c are shown in FIG. Here, the composite voltage vector of the B-phase detected voltage C has the same phase as the vector of the output voltage a' of the inverting amplifier 7. Therefore, the voltages a' and b.

The input terminal of the voltage detection amplifier 8, which has the voltage detectors 21 and 21! It is approximately twice as large as the voltage. Therefore, if the heavy voltage of the DC power supply I3 of the voltage detection amplifier 8 is set to a voltage slightly lower than approximately twice the negative phase voltage detection voltage, the comparator 14 will be The output becomes a positive level, the transistor 17 is driven, and an external output is generated. Furthermore, in the event of an open-phase vehicle failure or the 1114 trl pressure, the output of the comparator 14 becomes a negative level and the transistor 17 is controlled to be turned off.
No external output is generated. As mentioned above, according to the configuration shown in Fig. 1, there is no need to worry about the presence or absence of three-phase voltage of the high 1ri pressure machine! This can be easily determined using a single voltage detection amplifier.

In addition to the effects of the H0 invention, according to the present invention, voltage detection 1111 is installed close to a conductor of one phase. Induction of? d voltage is superimposed with U~, and the superimposed voltage is introduced into the voltage detection amplifier to form +, 11+, so the presence of three-phase voltage (Im can be detected, improving safety, and The voltage detection amplifier can be used as is, and three-phase voltage detection can be performed using one voltage detection amplifier 8. Therefore, cost reduction and space saving can be achieved.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a circuit diagram showing an example of a voltage detection amplifier, Fig. 3 is a three-phase voltage detection voltage vector diagram, and Fig. 4 is A-phase voltage detection. A voltage vector diagram showing the relationship between the voltage obtained by inverting the voltage and the B-phase and C-phase detection Tri voltages. FIG. 5 is an input voltage vector diagram of the voltage detection amplifier when there is three-phase heavy pressure. 1.2.3...A, Il, C phase main circuit conductor, 4,
5゜6... A, B, C phase detection electrodes, 7... Inverting amplifier, 8... Voltage detection amplifier! 1...Buffer, ■2.
... Rectifier, 13...+fl flow? n source, 14...
Comparator, I5゜1 (i, 1B...resistance, ■7.
...Transistor, 19...Relay coil. Figure 3 ii vector diagram for 2 other people

Claims (1)

[Claims] (1) In a three-phase voltage detection device for high-voltage equipment that performs voltage detection on high-voltage equipment through which three-phase current flows, the voltage detection electrodes are each disposed close to each phase conductor of the high-voltage equipment, and the voltage detection electrodes are provided. an inverting amplifier that inverts the phase of the induced voltage of a voltage sensing electrode that is placed close to a predetermined one-phase conductor; An alternating current voltage that is a superimposition of the induced voltage and the output voltage of the inverting amplifier is input, and a voltage detector that compares the voltage obtained by rectifying the alternating current input voltage with a predetermined set voltage to determine the presence or absence of voltage of the high voltage equipment. A three-phase voltage detection device for high voltage equipment characterized by being equipped with an amplifier.