JPS5830546B2 - Current detection relay - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power flow detection relay for a power flow circuit with power flow.

Generally, the average power factor of a consumer's load used for trading is calculated from the amount of power measured by a power meter and the amount of reactive power measured by a reactive power meter within a calculation period.

Currently, reactive watt-hour meters for calculating the power factor in systems with power flow are generally used as forward current meters equipped with a reversal prevention device, and the forward current is cut by the reversal prevention device.

However, in a system with power flow, if the current direction is reversed, the forward current is also measured and cannot be cut by the reversal prevention device, which is an inconvenience.

Additionally, as mentioned above, for consumers who have their own power generation equipment and purchase electricity from the electric power company (such as communal thermal power plants), the watt-hour meters are also equipped with reverse prevention devices for power purchase and charging purposes. Generally, each electric power company's supply regulations stipulate that electricity meters must be installed.

However, as described above, when the current of the reactive watt-hour meter is reversed, erroneous measurements occur, so it is necessary to detect the power flow and cut off the erroneous measurements when the current of the reactive watt-hour meter is reversed.

This invention was made in view of the above-mentioned points, and it is possible to generate electric power by receiving pulses from each of the power meters specified by the electric power company's general supply regulations, that is, the power transmitting power meter and the power receiving power meter equipped with a reverse prevention device. The purpose of the present invention is to provide a tidal current detection relay that detects tidal current.

An embodiment of the present invention will be described below. FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a waveform diagram for explaining the operation of each part in FIG. 1.

In FIG. 1, reference numeral 1a denotes a power meter with a transmitting device, which is equipped with a reversal prevention device, and is constructed so that if the current reverses, in the worst case, the rotating disk will stop after one rotation.

1a1. 1a2 1a3 is the pulse transmission output of the electricity meter with transmitter 1a, 1 al is the first phase pulse, 1a2
1a3 transmits the second phase pulse, and 1a3 transmits the third phase pulse.

And 1a during forward rotation. →1 a2→1 a3→1 a
Pulses are transmitted in the order of l..., and when reversing, 1 al
Pulses are transmitted in the order of →1 a3 →1 a2 →1a1.

Further, it is assumed that one or more pulses are transmitted for each revolution of the rotating disk of the power meter 18.

Further, it is assumed that 1a rotates in the normal direction when receiving power. 1b is a power meter with a transmitting device similar to the power meter with a transmitting device 13 described above.

It is also assumed that the motor rotates in the normal direction during power transmission.

1 bl + 1 b2 + 1 b3 is the pulse transmission output of the power meter with transmitter 1b, where 1 b1 transmits the first phase pulse, 1 b2 transmits the second phase pulse, and 1 b3 transmits the third phase pulse.

And during normal rotation, 1b1 → 1b2 → 1b3 → 1b1 ・
The pulses are transmitted in the order of...

When reversing, pulses are transmitted in the order of 1b1→1b3→1b2→1b1...

Further, it is assumed that one or more pulses are transmitted for each rotation of the rotating disk of the power meter 1b.

2a and 2b are phase sequence detection circuits, and the phase sequence detection circuit 2a receives as input the first phase pulse 1a1, second phase pulse 1a2, and third phase pulse 1a3 of the electricity meter with transmitter 13, and detects the phase sequence. When the rotation is normal like 1a1 → 1a2 → 1a3 →, H level output is sent to that output, and 1 al → 1 a
When the rotation is reversed, such as 3→1 a2→1 al..., an L level output is transmitted to that output.

Next, the phase sequence detection circuit 2b detects the first
Phase pulse 1b1, second phase pulse 1b2, third phase pulse 1
When b3 is input, its phase order is 1b1 → 11) 2 → 1b3 →
When the rotation is normal as in 1b1, an H level output is sent to the output, and when the rotation is in reverse as in lb, → 1b3 → 1b2 → 1b1, etc., an L level output is sent to the output.

3a and 3b are anti-slip circuits, and the anti-slip circuit 3a is configured as follows, for example.

3a1 is an N-ary counter provided corresponding to each phase pulse of the electricity meter 1a, that is, in this example, a ternary ring counter, for example, 3a2 corresponding to the first to third phase pulses.
t 3a3 y 3a4 is an AND circuit.

3a5 is an OR circuit, and 3a6 is a differential circuit. It is assumed that the anti-slip circuit is constituted by 3a and 3a6.

The first phase output of the ternary ring counter 3a is connected to one side of an AND circuit 3a2, and the first phase pulse 1a, 1 is connected to the other side of the AND circuit 3a2.

The second phase output of the ternary ring counter 3a1 is connected to one side of an AND circuit 3a3, and the second phase pulse 1a2 is connected to the other side of the AND circuit 3a3.

The third phase output of the ternary ring counter 3a1 is connected to one side of an AND circuit 3a4, and the third phase pulse 1a3 is connected to the other side of the AND circuit 3a4.

And AND circuit 3a2. The outputs of 3a3 and 3a4 are input to the OR circuit 3a5.

The differentiating circuit 3a6 generates an H level differential pulse when the OR circuit output changes from H level to L level.

The output thereof is connected to the clock input of the ternary ring counter 3a1.

It is assumed that the anti-slip circuit 3b is constructed in the same manner as the circuit 3a described above.

4a and 4b are NAND circuits.

5 is a flip-flop circuit, 6 is a resistor, 7 is a transistor, and 8 is a relay.

The relay 8 is composed of 8a to 8d, where 8a is a relay coil and 8b to 8d are contacts.

One input of the NAND circuit 4a receives the output of the differentiating circuit 3a6, and the other input receives the output of the phase sequence detection circuit 2a.

One input of the NAND circuit 4b receives the output of a latent movement prevention circuit 3b similar to the differential circuit 3a6, and the other input receives the output of the phase sequence detection circuit 2b.

The output of the NAND circuit 4a is connected to one input of the flip-flop circuit 5, and the output of the NAND circuit 4b is connected to the other input.

A resistor 6 is connected to one output of the flip-flop circuit 5.
It is connected to the base of the switching element transistor 7 via.

Further, the positive terminal of the power supply is connected to the collector of the transistor 7 via the relay coil 8a.

When one output of the flip-flop circuit 5 becomes H level, transistor 7 is turned on and relay coil 8a is energized, contacts 8b and 8d come into contact, and when it becomes L level, transistor 7 is turned off and relay coil 8a is energized. is deenergized and the contacts 8b and 80 are in contact with each other.

Next, the operation shown in FIG. 1 will be explained based on FIG. 2.

In FIG. 2, a is the output waveform diagram of the first phase pulse 1a1, b is the output waveform of the second phase pulse 1a2, and c is the output waveform of the third phase pulse 1a3.

d is the first phase output of the ternary ring counter 3a1, e is the second phase output of the ternary ring counter 3a1, and f is the third phase output of the ternary ring counter 3a.

g is an OR circuit 3a. Output waveform diagram, h is differentiator circuit 3a6
i is an output waveform diagram of the phase sequence detection circuit 2a,
j is an output waveform diagram of the NAND circuit 4a.

t1 to t5 indicate time course tl → t2 → t3 → t4
It is assumed that time elapses in the order of →t5.

For convenience of explanation, the watt-hour meter is illustrated as rotating at a constant speed.

Next, to explain the operation, the periods of tl are a and b.

As shown in C, pulses are transmitted in the order of 1a1 → 1 a2 → 1 a3, and the differential circuit 3 is transmitted at the trailing edge of the output of the OR circuit 3a5.
It is output from a6.

The ring counter 3a1 is always in a state ahead of the first to third phase pulses 1a1 to 133.

Therefore, the electricity meter 1a moves latent and 1a1 tla211
Even if a3 causes a pulse break, this pulse and the output of the ring counter 3a1 are connected to the AND circuit 3a2゜3a3t3.
An AND is taken at a4, and the output of the AND circuit is used as the output of the OR circuit 3a5.For example, a double pulse is not generated by the pulse circumcision double pulse of the first phase pulse.

For example, the first phase pulse 1 of the electricity meter 13 with transmitter
When a1 has a pulse break, and if the pulse in the preceding part of this pulse break is al, the differentiating circuit 3a6 generates a corresponding differential pulse h1 at the trailing edge of the pulse a1, and sets the ternary ring counter 3a1 to 1. Since the second phase pulse 1a2 is in the standby state, the above 1.
Upon input of the phase pulse 1a1, the latent motion prevention circuit 3a only generates a single pulse regardless of the pulse cracking (or slight forward/reverse operation).

On the other hand, at this time, the other watt-hour meter 1b with a transmitting device is locked by the reverse rotation prevention device and is in a state in which no pulse should be generated.

Correspondingly, the movement of the latent movement prevention circuit 3b prevents the generation of pulses due to pulse breakage (or slight forward/reverse operation).

And the phase sequence detection circuit 2a is 1al→1 a2→1a3
Since pulses are received in the order of →1a1, an H level output is generated as shown in waveform i.

Therefore, the NAND circuit 4a generates an output like J.

Next, during period t2, the reverse rotation starts from the second phase pulse 1a2.

Then, pulses are generated in the order of 1a2 → 1a1 → 1a3 → 1a2 .

Further, the phase order detection circuit 2a detects a reversal at the leading edge of the open phase pulse as shown in 1a2→1a1, and its output falls to the L level as shown at i.

Therefore, the output j from the NAND circuit 4a is not output.

Moreover, the period t2 indicates that the rotation has started again in the normal direction after the second phase pulse 1a2 has passed.

Then, the phase sequence detection circuit 2a detects normal rotation at the leading edge of the next phase pulse 1a3 of the second phase pulse 1a2, and outputs an H level.

Then, the output of the ring counter 3a1 and the transmission pulse 131
When ~1as matches, the differential circuit 3a6 starts at the trailing edge.
However, since the output of the phase sequence detection circuit 2a is at H level, the NAND circuit 4a outputs an output again.

Next, regarding period t4, it is shown that the rotating disk started to reverse from the third phase pulse 1a3 and immediately stopped by the reverse rotation prevention device of the watt-hour meter 1a.

In this case, the phase order detection device 2a detects the next phase pulse during reverse rotation from the third phase pulse 1a3, that is, the second phase pulse 1a2.
Since no signal is sent, reverse rotation cannot be detected and the forward rotation output H level is output.

However, the reversal prevention device of the electricity meter 1a is activated, and the OR circuit 3as does not fall from the H level to the L level.

Therefore, no output is produced from the differentiating circuit 3a6 or from the NAND circuit 4a.

Furthermore, even if the third phase pulse 133 causes a pulse break, the ring counter 3a1 advances to the next phase, so that only one pulse is output.

Next, period t5 indicates that normal rotation has started again.

As before, the output from the NAND circuit 4a is again sent to the electricity meter 13.
Rotation I of □ is outputted.

Power meter with transmitter equipped with a reverse rotation prevention device 1
Although we have described each case of forward and reverse of a, the NAND circuit 4a
It can be seen that in the case of forward rotation, L level pulses are transmitted one after another in accordance with the rotational speed of the rotating disk, but in the case of reverse rotation, they are not transmitted.

Also, in the above, only the watt-hour meter 1a system was described, but the watt-hour meter 1b system is connected in exactly the opposite way to the watt-hour meter 1a system, so the NAND circuit 4a
When L level pulses are being transmitted continuously, there is no output from the NAND circuit 4b, and when there is an output from the NAND circuit 4b, no output is from the NAND circuit 4a.

Since the output of each NAND circuit 4av4b is connected to each input of the flip-flop circuit 5, the state of the flip-flop circuit 5 is inverted by each input.

Therefore, the relay 8 is driven by the flip-flop circuit 5 via the transistor 7, but when the watt-hour meter 1a is rotating normally, the relay coil 8a is energized and the watt-hour meter 1b is energized.
is deenergized when it is rotating in the normal direction.

Therefore, depending on the states of contacts 8b to 8d of relay 8, it can be determined which wattmeter is rotating in the forward direction or in the reverse direction (power transmission or power reception).

Furthermore, it is possible to switch between measurement and non-measurement of the reactive energy meter by using, for example, an auxiliary relay.

In the above, in this invention, the example of the three-phase pulse has been described.
For example, the phase order may be determined by wrapping the first phase and the second phase in one part, and if there are two or more phases, this becomes possible depending on the ability of the phase order detection circuit.

Further, according to the present invention, it is also possible to count each input and display and measure only the determination of power transmission and power reception.

As described above, according to the present invention, it is possible to determine whether power is being transmitted or received by introducing each pulse from the watt-hour meter with a reversal prevention device.

Furthermore, there is no problem even if the reverse rotation prevention device operates immediately or, in the worst case, rotates once.

In addition, since the watt-hour meter with a reverse rotation prevention device can be used as is, the amount of electricity can be measured with high accuracy.

It is also convenient because a standard watt-hour meter can be used without changing the transaction format currently in use.

Furthermore, since power transmission and reception can be processed using only a pulse circuit or a low DC voltage, it can be processed compactly and is extremely convenient to handle.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of one embodiment of this invention, and FIG.
FIG. 3 is a waveform diagram for explaining the operation of each part in the figure. In the figure, 1a is a watt-hour meter with a transmitter, 1b is a watt-hour meter with a transmitter, 2a and 2b are phase sequence detection circuits, 3a and 3b
3a1 is an N-ary counter (ternary ring counter), 4a and 4b are NAND circuits, 5 is a flip-flop circuit, and 7 is a switching element.

Claims (1)

[Claims] 1 In a power flow circuit with a power flow, a first watt-hour meter with a transmitter equipped with a reversal prevention device that rotates in the normal direction and emits a multiphase normal pulse when receiving power, and a power meter with a first transmitting device that rotates in the normal direction and emits a multiphase pulse when transmitting power. A second watt-hour meter with a transmitting device equipped with a reversal prevention device for transmitting, a phase-sequence detection circuit provided corresponding to each of these watt-hour meters and determining the phase order of the multiphase pulses, and each of the watt-hour meters. has an N-ary counter that is provided corresponding to each phase pulse and operates in advance of the operation of the watt-hour meter,
an anti-slip circuit that outputs a single pulse when each output from the counter matches a pulse from the watt-hour meter;
It is equipped with a flip-flop circuit whose input terminal is the AND output of a phase sequence detection circuit and a slippage prevention circuit corresponding to each of the above-mentioned watt-hour meters, and a switching element controlled by the output of this flip-flop circuit. A power flow detection relay that determines whether the power flow is transmitting or receiving power based on the output of the switching element.