JPS60104268A - Power source discriminating circuit - Google Patents

Abstract

PURPOSE:To discriminate the kind of AC power source by simple circuit constitution by applying a processing such as exclusive OR, the elimination of a prescribed pulse, etc. with respect to a binary pulse corresponding to two AC voltage information fetched from a power source line. CONSTITUTION:Two AC voltage signals V12, V32 fetched from the power source line of a single phase two-wire system or three-phase three-wire system power source are converted to binary pulse signals 103, 104 by operational amplifiers 41, 42 of a zero crossing comparator, etc., respectively, processed by an exclusive OR circuit 5, and a clock 105 of its output becomes a wide clock and a whisker- like clock in case of a three-phase power source and in case of a single-phase power source, respectively. This narrow clock 105 is eliminated, an integration circuit 6 outputs a high level signal in response to the wide clock, an FF7 is controlled, and when a Q output of the FF7 is in a high level, whether the AC power source is three phase or single phase is discriminated in accordance with the time of a low level. In such a way, the kind of AC power source can be discriminated by simple circuit constitution.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a power supply discrimination circuit that discriminates the type of power supply applied to a load [Technical Background of the Invention] Single-phase and three-phase J-wire power loads In a shared analyzer used to understand the usage status of a load (e.g. electric power, apparent power, power factor, etc.), the wiring method shown in Figs. It is common to input voltage information.

Figure 1 shows the wiring method when the power supply is a three-phase three-wire system or a single-phase three-wire system.The voltage input section is connected from the power supply line connecting the power supply l and the load co through input terminals P1 * P2 * P3. Two sets of AC voltage information are given to 3. The power input section 3 is composed of two transformer circuits 3/32, the input terminals P and P are connected to the input of one transformer circuit 31, and the terminals P2 and P3 are connected to the input of the other transformer circuit 32. is connected to the input of

Here, of the three power lines connecting power supply l and load co, the - phase (R phase) wire goes to terminal F, the two-phase (S phase) wire goes to terminal P, and the three-phase wire goes to terminal P. (T phase) wires are connected to terminals ps, respectively, and λ transformer circuits 3/.

The voltages 712 #vn transformed by the three converters are each input to a calculation section of an analyzer (not shown), and the type of the power source I is determined.

Figure 1 shows the wiring method when the power supply l' is a single-phase two-wire type, and one phase wire of the two power supply lines connecting the power supply l' and the load a' is connected to the terminal P. , , P3 and two-phase lines are respectively input to the terminal P2. In this case, the transformer circuit 3/
The output voltage '712 from the transformer circuit 3.2 and the output voltage V32 from the transformer circuit 3.2 are in-phase signals.

[Problems with background technology]

AC voltage information (v
+21 VB2 ) and the current information flowing to the load,
When calculating the analytical data to understand the usage status of the load, for example, when calculating the apparent power, in the case of a three-phase three-wire system, the line voltage is input as shown in Figure 1, so it is difficult to calculate the apparent power of a single-phase system. Unlike the apparent power behavior in case of It is necessary to switch the arithmetic processing. Therefore, in the past, the operator set the type of power supply using a setting device installed in the analyzer, but if the setting items were complex, it could lead to setting errors. There were a number of operational problems, such as the need for skill and skill in handling the equipment. Therefore, there has been a demand for a technology that automatically determines the type of power source without troubling the operator.As a method for automatically determining the type of power source, the methods shown in Figures 1 and 2 are shown in Figures 1 and 2. There is a method of using voltage information VI2 and VB2 obtained by the wiring method, converting this into pulses, and automatically determining the type of power source based on the order in which the pulses rise.

FIG. 3 is a vector diagram showing the phase relationship between the voltages V12 and vs□ obtained by the circuits shown in FIGS. 1 and 2. FIG. 3(a) shows a vector diagram when the power source is a three-phase J-wire system, and the voltages ÷2 and ÷32 have a phase difference of 6θ°. Figure 3 (wa) shows 1. This is a vector diagram when the source is single-phase 3-wire, and the voltage is divided by 2.

and has a phase difference of /gO°. Furthermore, Figure 3 (C
) shows a vector diagram when the power supply is single-phase, two-wire type, and the voltage and ÷32 are in phase.Using the phase relationship of the voltage information of this group, the voltage ÷, 2 can be calculated. The rising order of the converted pulse and the voltage divided by 2 (
However, as shown in Figures 3(b) and 3(c), in single-phase 3-wire systems and single-phase 2-wire systems, the phases of the two voltage signals are Since the angles differ by /gθ°, in order to determine the type of power supply, the voltage ÷ +
A circuit is required to delay (or advance) the rise time (or fall time) of the pulse by different times for the conversion pulse of 2 and the conversion pulse of voltage ÷ y, making the discrimination circuit complicated. There was a drawback.

[Purpose of the invention]

An object of the present invention is to provide a power source discrimination circuit that can automatically discriminate the type of power source with a simple circuit configuration.

[Summary of the invention]

In this invention, in order to achieve the above object, single phase or Fi
In a power supply discrimination circuit that discriminates the type of power applied to the power supply line using two pieces of AC voltage information extracted from three-phase power supply lines, the two pieces of AC voltage information are input to the first and first circuits, respectively. means for converting into a value pulse signal, means for calculating an exclusive OR of the first and first value pulse signals, and means for removing pulses having a predetermined pulse width or less from the exclusive OR signal. is provided, and the type of power source is determined based on the output of the pulse removal means.

[Embodiments of the invention]

FIG. 3 is a circuit diagram showing an embodiment of the present invention. m/
The λ pieces of AC voltage information VI21V32 outputted from the power input unit J shown in FIGS. Each converted pulse signal is input to an exclusive OR gate S. The output of the exclusive OR gate S is the integrator circuit t.
It is connected to the flip-flop 7 via. In addition, the reset circuit g is connected to the clear terminal (OL) of flip-flop 7.
is connected.

Next, the operation of the circuit shown in FIG. 5 will be explained using the timing chart shown in FIG. Note that FIG. S (a) is a timing chart for a three-phase three-wire power supply, (1)) is a timing chart for a single-phase three-wire power supply, and (C) is a timing chart for a single-phase λ-wire power supply.

Waveform of AC voltage v12*V32 10/, 10;
Since the phase difference of l varies depending on the type of power source as shown in FIG. 3, it becomes as shown in FIG. 5. This waveform 10/
.

102 Waveform 1 is converted to a value pulse signal using 11.2 to an arithmetic amplifier such as a zero cross comparator.
0J, IO'l. exclusive disjunction) s is 2
When the states of two input signals are low and high or a combination of high and low, the output becomes high level, and when the states of the two input signals are low and low or a combination of high and high, the output becomes low level. Therefore, for the input waveform 10J, /θg, the output waveform ios is as shown in Figure S (a) in the case of a three-phase J-wire power supply.
) The clock waveform is obtained as shown in ().

In the case of single-phase three-wire and single-phase two-wire power supplies, ideally they are fixed at high level and low level, respectively, but in reality there may be a phase difference of several degrees. Therefore, as shown in Fig. S (1) and (c), whisker-like clocks are generated in the output waveform 10s.

An integrating circuit 6 is used as a means for removing this whisker-like clock.

Here, t during pulse removal by integrating circuit B is 1°:>1)
There is a relationship of 12.13. In addition, 1. is the clock width of the waveform ios in the case of a three-phase three-wire power supply, and 12.1B is the single-phase J i1i! The equation is the output waveform/the whisker-like clock width of θ5 in the case of a single-phase λ line power source. Therefore, the clock pulse passes only in the case of a three-phase l-wire power supply, and the single-phase J
In the case of a wire type or single-phase two-wire type power supply, the whisker-shaped clock is removed. The output waveform iob of the integrated integration circuit B and the output waveform 107 of the flip-flop 7 are as shown in FIG.

Note that the reset circuit g is the output (Q) of the flip-flop
It outputs a signal to set the to the initial state.

As is clear from the waveforms IOA and 107 in FIGS. 5(b) and 5(C), the type of power supply in the case of the conventional inner cone type single-phase three-wire type and single-phase co-wire type is expressed by the output waveform-104, This can be easily determined by whether 107 is high, low, or low.

FIG. 6 shows another embodiment of the present invention, in which the output of the private circuit B is manually input to a monostable multivibrator T to obtain a stable output 109. As shown in Figure 7(d), the monostable martenometer starts at the rising edge (or falling edge) of the input pulse.
This is a circuit that can obtain an output pulse with a constant pulse width tw), but as shown in FIG.
) is input, a restart (mu mark) is applied during output, and the output is always held at a constant level (high level). In other words, the length of 1 W during the output of the monostable multivibrator t is longer than the clock width of the waveform 104 (by doing so, the same result as in FIG. 10 described above can be obtained).

FIG. 3 is a circuit diagram showing another embodiment of the present invention, in which the output of the exclusive OR gate 5 is passed through the integrator IO to the arithmetic multipliers 1 for voltage level determination. In this case, a stable output /// a +' /// b is obtained.

Then, as shown in FIG. 9(f), the exclusive OR gate s
The waveform 10s that has passed through is (a), ('t)), (c) depending on the three-phase three-wire system, single-phase three-wire system, and single-phase co-wire system, respectively.
The output waveform I10ij is integrated by the integrator IQ and converted into a voltage level as shown in FIG. 9(g). In other words, if the voltages in each of the three-phase J-wire, single-phase J-wire, and single-phase two-wire power supplies are Va, Vb, and Vc, the relationship between the voltage levels is as follows.
O≦vc (va<vb≦maximum output voltage of the integrator 10. Here, the comparison voltage V, , V2 is set to the operational amplifier //a, so that Vc<, V, <Va<v2 <vb. //b
By connecting it to one input terminal of the integrator 10 and comparing the output of the integrator 10, it is possible to obtain combinations of values of the values as shown in FIG. 9(h) depending on the type of power supply. can get. Therefore, by comparing these values, the type of each power source can be easily determined.

Note that in the case of a three-phase l-wire power source, the same calculation process as for a single-phase a-wire power source may be used. It goes without saying that the present invention can also be applied to analyzers that can be used in common regardless of whether they are single-phase or three-phase and wire type.

〔Effect of the invention〕

As described above in detail based on the embodiments, the present invention converts two AC voltage information extracted from a single-phase or three-phase power supply line into a value pulse signal, and then converts the exclusive OR signal into a predetermined pulse signal. Since the type of power source is determined based on the signal obtained by removing pulses below pulse [1], there is an advantage that the type of power source can be determined with a relatively simple circuit configuration.

[Brief explanation of the drawing]

Figures 1 and 2 are voltage input wiring diagrams for obtaining AC voltage information from the power supply line, and Figures 3 (ai, (b), (c)
) is a voltage 4-volt diagram depending on the type of power supply, Figure 9 is a circuit diagram showing an embodiment of the present invention, and Figures S (a) and (D)
, (C) is a timing chart showing the operation of FIG. 9, FIG. 6 is a circuit diagram showing another embodiment of the present invention, and FIG. 7(d). (e) is a timing chart 1 for explaining the operation of FIG. 6, and FIG. 5 is a circuit diagram showing still another embodiment of the present invention. 5 is a timing chart for explaining the operation of FIG. 5. FIG. l...Power supply, 2...Load, J...Voltage input section, R/, Dakko...Arithmetic amplifier, S...Exclusive OR gate, 6...Integrator circuit, 7 ···flip flop,?
...monostable multivibrator, IO...integrator. Applicant's agent Inomata Ichigami 2] Yu 12 'J2 Gu? fI2 Z/32 (=zrlz) (C) ===== No good? f3z

Claims (1)

[Claims] In a power supply determination circuit that determines the type of power applied to the power supply line using λ pieces of AC voltage information taken out from a single-phase or three-phase power supply line, the two AC voltage information are used as first and second AC voltage information, respectively. means for converting the first and second binary pulse signals into a binary pulse signal; means for calculating an exclusive OR of the first and second binary pulse signals; What is claimed is: 1. A power supply discriminating circuit comprising: means for removing pulses, and discriminating the type of power supply based on the output of the pulse removing means.