KR102753643B1 - Apparatus and Method for measuring power using direction recognition - Google Patents

Abstract

A direction-detecting power metering device that measures both received power and generated power with a single power meter is disclosed. The direction-detecting power metering device is characterized by including a classifier that detects the current direction of generated current flowing in a power line, a bidirectional power meter that accumulates power by using received current by on-site power if the current direction is forward or by using generated current if the current direction is reverse, and a converter that converts power lower than the generated current and transmits it to the bidirectional power meter if the current direction is reverse.

Description

{Apparatus and Method for Measuring Power Using Direction Recognition}

The present invention relates to power metering technology, and more specifically, to a directional sensing power metering device and method for measuring both received power and generated power with a single power meter.

In the case of solar power plants, the power line thickness and metering device are configured according to the generation capacity. For example, in the case of 99 kW of generation, 3 kW of on-site power is received and used, but the meter measures it using a CT (Current Transformer) (200 A → 5 A) and a CT unit instrument so that it can handle 99 kW.

However, in the case of nights when there is no solar power generation, the power usage in the building must be measured, but there are cases where the total is not calculated because the current value is lower than the minimum starting current through CT (200/5). In addition, since a large-capacity meter is installed even though the receiving current is small, there is an inherent possibility of under-measuring if the receiving current is lower than the starting current at the meter.

Therefore, after installing the CT, two power meters, one for the hydroelectric power meter and one for the generated power meter, were reverse-connected to measure the power.

1. Korean Patent Registration No. 10-1484640 (Registration Date: 2015.01.14)

The present invention has been proposed to solve the problems according to the above background technology, and its purpose is to provide a directional detection power metering device and method that measures both received power and generated power with one bidirectional power meter.

In order to achieve the above-mentioned task, the present invention provides a directional sensing power metering device that measures both received power and generated power with a single power meter.

The above directional sensing power metering device,

A classifier that detects the current direction of the generated current flowing in a power line;

A bidirectional power meter that accumulates power by using the received current due to the power in the power plant if the current direction is forward, or by using the generated current if the current direction is reverse; and

It is characterized by including a power conversion unit that converts power lower than the generated current and transmits it to the bidirectional power meter when the current direction is reversed.

At this time, the classifier is characterized by including a direction sensor that detects the current direction; and a variable resistor that changes the resistance so that the receiving current flows into the bidirectional power meter when the current direction is positive.

In addition, the variable resistor is characterized as being a digital variable resistor.

In addition, the variable resistor is characterized in that it is selectively connected to a first connecting line arranged to allow the receiving current to flow into the bidirectional power meter and a second connecting line arranged to allow the generating current to flow into the power converter.

In addition, the direction sensor is characterized by detecting the forward or reverse direction using a Hall sensor.

In addition, the above-mentioned converter is characterized by being a CT (Current Transformer).

In addition, the bidirectional power meter is characterized in that it integrates power by applying CT multiple only in the case of the generated current. Here, the CT multiple means the transformation ratio of the CT primary side and secondary side.

In addition, the bidirectional power meter is characterized in that only one is installed.

On the other hand, another embodiment of the present invention provides a directionality detection power metering method, characterized by including: (a) a step in which a classifier detects a current direction of a generated current flowing in a power line; (b) a step in which a converter receives the generated current if the current direction is reverse, converts the generated current into power lower than the generated current, and transmits the converted power to the bidirectional power meter; (c) a step in which the bidirectional power meter integrates power using the received current by the in-house power if the current direction is forward, or integrates power by receiving the generated current if the current direction is reverse.

According to the present invention, both received power and generated power can be measured with one power meter.

In addition, another effect of the present invention is that it can prevent damage due to underestimation of internal power. In other words, it can prevent damage of about 2 billion won = 2,000 won per solar power generation site x 1 million households.

In addition, another effect of the present invention is that it can enhance the company image through transparent development transactions.

FIG. 1 is a block diagram of a directional sensing power metering system according to an embodiment of the present invention.
Figure 2 is a detailed block diagram of the classifier illustrated in Figure 1.
Figure 3 is a detailed block diagram of the direction sensor illustrated in Figure 2.
FIG. 4 is a flowchart showing a power metering process through direction detection according to one embodiment of the present invention.

The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and the embodiments are provided only to make the disclosure of the present invention complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. The sizes and relative sizes of the components shown in the drawings may be exaggerated for the clarity of explanation.

Throughout the specification, like reference numerals refer to like elements, and “and/or” includes each and every combination of one or more of the items mentioned.

The terminology used herein is for the purpose of describing embodiments only and is not intended to be limiting of the invention. In this specification, the singular also includes the plural unless the context clearly dictates otherwise. As used herein, the terms “comprises” and/or “consists of” do not exclude the presence or addition of one or more other components, steps, operations, and/or elements.

Although the terms first, second, etc. are used to describe various components, it is to be understood that these components are not limited to these terms. These terms are used only to distinguish one component. Accordingly, it is to be understood that the first component mentioned below may also be the second component within the technical concept of the present invention.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used with a meaning that can be commonly understood by a person of ordinary skill in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries shall not be ideally or excessively interpreted unless explicitly specifically defined.

Hereinafter, a direction-sensing power metering device and method according to an embodiment of the present invention will be described in detail with reference to the attached drawings.

Fig. 1 is a block diagram of a direction-sensing power metering system (100) according to one embodiment of the present invention. Referring to Fig. 1, a direction-sensing power metering device (100) may be configured to include a classifier (110), a power converter (120), a bidirectional power meter (130), etc.

The classifier (110) detects the direction of the generated current and controls the flow of the generated current. In detail, the classifier (110) measures voltage and current, and if the current is in the reverse direction, that is, if the current flows from right to left by the distributed power generation source (140), it is determined that solar power generation is generated and is fed into the bidirectional power meter (130) through the power converter (120). Normally, solar power generation consumes only on-site power at night after sunset, so a forward current that flows from left to right flows, and if the amount of solar power generation after sunrise becomes greater than the amount of on-site power, a reverse current flows.

The power line (10) and the connection line (112) are connected to each other.

To elaborate, in the case of a solar power plant, the thickness of the power line (10, 20) and the power conversion unit (120) are configured according to the power generation capacity.

For example, in the case of a power generation of 99 kW, 3 kW of on-site power is received from the power company separately from the generated current from the solar power plant, but the bidirectional power meter (130) must be measured using a power conversion unit (120) so that it can handle 99 kW.

In contrast, if the current is in the forward direction, the power within the cell flows from left to right, and in this case, the shunt (110) allows the power within the cell to flow to the connecting cable (111) so that the power within the cell can be directly accumulated in the bidirectional power meter (130).

The distributed power source (140) represents power generated from a solar power plant. Therefore, the distributed power source is connected to the right side of the power conversion unit (120). The K terminal of the power conversion unit means the power company's power terminal, and the L terminal means the power plant terminal. The on-site power can measure the on-site power used in the power plant when there is no solar power generation. The on-site power is the power required for all devices directly or indirectly related to the operation of the power plant. That is, it can be a monitoring device, a light, a ventilator, a control computer, an inverter, etc.

FIG. 2 is a detailed block diagram of the classifier (110) illustrated in FIG. 1. Referring to FIG. 2, the classifier (110) may be configured to include a measuring sensor (210) for measuring current and voltage, a direction sensor (220) for detecting the direction of current, an amplifier (230) for amplifying the detected signal, a variable resistor (250) for changing the direction of current by varying the resistance, a controller (240) for controlling by exchanging signals with these components, etc.

The measurement sensor (210) performs the function of measuring the voltage and/or current of the power line (10, 20). For this purpose, the measurement sensor (210) may be composed of a current sensor, a voltage sensor, etc. As the current sensor, a Hall sensor, an optical fiber current sensor, a CT (Current Transformer) type current sensor, etc. may be used.

The direction sensor (220) detects whether the direction of the current flowing in the power line (10, 20) is reverse or forward.

The amplifier (230) performs the function of amplifying a signal generated from the direction sensor (220) and transmitting it to the controller (240). An operational amplifier (OP AMP) or the like may be used as the amplifier (230).

The variable resistor (250) is a digital variable resistor that receives a control signal from the controller (24) and has a function of varying the resistance. That is, it performs a function of selectively increasing the resistance to the first connection line (111) or the second connection line (112) to allow current to flow. In detail, the first connection line (111) is selectively connected to the first connection line (111) arranged to allow the internal power to flow into the bidirectional power meter (130) and the second connection line (112) arranged to allow the generated current to flow into the power conversion unit (120). The power conversion unit (120) may be a CT (Current Transformer). In detail, the power conversion unit (120) performs a function of converting 200A into 5A.

In other words, if the detected current direction is reverse, the resistance of the variable resistor (250) is lowered so that the generated current flows toward the power conversion unit (120). That is, the resistance toward the first connection line (111) is increased, and the resistance toward the second connection line (112) is lowered so that the generated current flows toward the second connection line (112).

In contrast, if the detected current direction is positive, the resistance of the variable resistor (250) is increased so that the internal power (i.e., internal current) flows into the first connection line (111) and thus flows into the bidirectional power meter (130). That is, the resistance on the first connection line (111) side is lowered, and the resistance on the second connection line (112) side is increased so that the generated current flows into the second connection line (112) side.

The controller (240) detects the direction of the current and performs the function of controlling the variable resistance accordingly. To this end, the controller (240) may be configured to include a microprocessor, a switching circuit, a supply, etc.

Figure 3 is a detailed block diagram of the direction sensor (220) illustrated in Figure 2. Referring to Figure 3, the direction sensor (220) is configured to include a magnetizing core (320), a Hall sensor (340), a driving unit (310), etc., which are inserted into a hollow space where a power line (10) is formed.

The magnetizing core (320) can sense the strength of a magnetic field generated by an input current that is a target of measurement. The input current can flow along a power line (10) located in the center of the magnetizing core (320). The input current applies a magnetic field to the magnetizing core (320) by Ampere's right-hand rule, which is the most basic law of electromagnetism, and therefore, a detailed description thereof will be omitted.

The magnetizing core (320) is generally formed in a circular band shape so that the magnetic field formed by the input current can be applied most efficiently. The strength of the magnetic field that can be saturated is determined for each magnetizing core (320).

A Hall sensor (200) is formed on one side of the magnetized core (100) and can generate an output voltage by the magnetic field.

The Hall sensor (340) refers to a device that generates a voltage according to a magnetic field by utilizing the Hall effect in which a potential difference is generated when a magnetic field is applied. In one embodiment of the present invention, the magnetic field is measured using the Hall sensor (340), and the current direction is determined through the direction of the magnetic field. In other words, a potential difference is generated by the Hall effect, and a Hall voltage is formed by this electromotive force. If the direction of the current movement or the direction of the magnetic field is changed, the Hall effect and the Hall voltage also become opposite accordingly. For example, a + voltage can be set to a positive direction, and a - voltage can be set to a reverse direction.

The driving unit (310) can rotate the magnetizing core (320) so that the core angle formed by the central axis of the magnetizing core (320) and the input current direction is changed. The driving unit (310) can be formed by including a motor that rotates the magnetizing core (320). The driving unit (310) can be operated by a driving signal generated by a controller (240) described below.

Fig. 4 is a flowchart showing a power metering process through directionality detection according to one embodiment of the present invention. Referring to Fig. 4, voltage and current measurements are performed in a directionality recognition classifier (step S410).

Afterwards, the current direction is detected in the direction recognition classifier (step S420).

Thereafter, when the current direction is detected, the controller (240) determines whether the current direction is reverse or forward (step S430). In other words, it determines whether the current is generated by a distributed power source or received by the local power source.

As a result of the judgment, in step S430, if it is reverse, the generated current flows to the bidirectional power meter (130) side through the CT (120) by the variable resistor. Thereafter, the bidirectional power meter (130) applies the CT multiplier only to the generated power (i.e., the generated current) and accumulates the power amount (steps S440 and S450). Here, the CT multiplier means the current transformation ratio of the CT primary side and secondary side. For example, in the case of 200A/5A CT, the CT multiplier is 40 times.

In contrast, if the judgment result is positive at step S430, the current is caused to flow directly to the bidirectional power meter (130) without passing through the CT (120) by the variable resistor, so that the bidirectional power meter (130) accumulates the power (steps S431 and S450).

In addition, the steps of the method or algorithm described in connection with the embodiments disclosed herein may be implemented in the form of program instructions that can be executed by various computer means, such as a microprocessor, a processor, a CPU (Central Processing Unit), and the like, and recorded on a computer-readable medium. The computer-readable medium may include program (instruction) codes, data files, data structures, etc., alone or in combination.

The program (command) code recorded on the above medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium may include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs, DVDs, and Blu-rays, and semiconductor memory devices specially configured to store and execute program (command) codes such as ROMs, RAMs, and flash memories.

Here, examples of program (instruction) code include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc. The above-mentioned hardware device can be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

100: Directional Sensing Power Metering Device
110: Classifier
120: CT(Current Transformer)
130: Bidirectional power meter
140: Distributed power generation

Claims (16)

A classifier (110) for detecting the current direction of the generated current flowing in the power line (10,20);
A bidirectional power meter (130) that accumulates power by using the received current due to the power in the power plant if the current direction is forward, or by using the generated current if the current direction is reverse; and
A power conversion unit (120) that converts power lower than the generated current and transmits it to the bidirectional power meter (130) when the current direction is reversed;
A directional sensing power metering device characterized by including a .
In paragraph 1,
The above classifier (110) is
A direction sensor (220) for detecting the current direction; and
A directional sensing power metering device characterized by including a variable resistor (250) that varies the resistance so that the receiving current flows toward the bidirectional power meter (130) when the current direction is positive.
In the second paragraph,
A directional sensing power metering device, characterized in that the above variable resistor (250) is a digital variable resistor.
In the third paragraph,
A directional sensing power metering device characterized in that the variable resistor (250) is selectively connected to a first connecting line (111) arranged to allow the receiving current to flow into the bidirectional power meter (130) and a second connecting line (112) arranged to allow the generating current to flow into the power converter (120).
In the second paragraph,
A direction-detecting power metering device characterized in that the direction sensor (220) detects the forward or reverse direction using a Hall sensor.
In paragraph 1,
A directional sensing power metering device characterized in that the above-mentioned converter (120) is a CT (Current Transformer).
In paragraph 6,
The above bidirectional power meter (130) is a directional detection power metering device characterized in that it calculates power quantity by applying CT multiple only in the case of the generated current, and the CT multiple means the transformation ratio of the CT primary side and secondary side.
In paragraph 1,
A directional detection power metering device characterized in that only one bidirectional power meter (130) is installed.
(a) a step in which a classifier (110) detects the current direction of the generated current flowing in the power line (10, 20);
(b) a step in which the conversion unit (120) receives the generated current when the current direction is reversed, converts it to power lower than the generated current, and transmits it to the bidirectional power meter (130);
(c) a step of accumulating power by using the received current due to the power within the power plant if the current direction of the bidirectional power meter (130) is positive, or accumulating power by receiving the generated current if the current direction is reverse;
A directional sensing power metering method characterized by including a.
In Article 9,
The above classifier (110) is
A direction sensor (220) for detecting the current direction; and
A directionality detection power metering method characterized by including a variable resistor (250) that varies the resistance so that the receiving current flows toward the bidirectional power meter (130) when the current direction is positive.
In Article 10,
A directional sensing power metering method, characterized in that the above variable resistor (250) is a digital variable resistor.
In Article 11,
A directional sensing power metering method, characterized in that the variable resistor (250) is selectively connected to a first connecting line (111) arranged to allow the receiving current to flow into the bidirectional power meter (130) and a second connecting line (112) arranged to allow the generating current to flow into the power converter (120).
In Article 10,
A direction detection power metering method characterized in that the direction sensor (220) detects the forward or reverse direction using a Hall sensor.
In Article 9,
A directional sensing power metering method, characterized in that the above-mentioned converter (120) is a CT (Current Transformer).
In Article 14,
The above bidirectional power meter (130) calculates power quantity by applying CT multiple only in the case of the generated current, and the CT multiple means the transformation ratio of the CT primary side and secondary side. A directional detection power metering method.
In Article 9,
A directional detection power metering method characterized in that only one bidirectional power meter (130) is installed.