JP6136481B2 - Power measuring apparatus and power measuring system - Google Patents

Description

  The present invention relates to a technique for controlling the phase balance of a power supply when distributing and distributing three-phase AC power to single-phase power in a power distribution system in a facility such as a factory, store, building, or data center.

  In power distribution systems in facilities such as factories, stores, buildings, and data centers, it is necessary to consider phase balance when distributing single-phase AC power received and supplying single-phase power to branch loads. is there.

  Therefore, for example, in the distribution of distribution boards and bus ducts, the phase balance is confirmed by the host device using information such as the power measured in the plug-in units (hereinafter referred to as PIUs) installed in a distributed manner. How to do is known. Information acquired by the host device is used, for example, during power supply or load expansion work.

  As a known technique for maintaining the balance of the three-phase phase current in a circuit configuration that takes a single-phase power supply from a three-phase AC circuit, for example, determine which phase should be grouped from the load current value of each load, and load each load A technique for controlling connection to each phase of the above is disclosed (for example, Patent Document 1). According to this, the combination of loads that can be connected to each phase is determined, and the resistance value of the variable resistor is controlled by providing a variable resistor for adjusting the load current between any phase and each load. Alternatively, the phase current balance is maintained, for example, by disconnecting a phase load having a phase current difference of a predetermined value or more.

Japanese Unexamined Patent Publication No. 7-31058

  According to the conventional method of monitoring by the host device, the power state and capacity are monitored at a location away from the site where the load is actually connected such as a remote server. By the way, even when wiring is added to the distribution board for expansion work or the like, information such as capacity is required. However, in the conventional monitoring method using the host device, it is necessary to take power outage measures during expansion work or the like. For this reason, it is difficult to say that the information held by the host device is effectively utilized.

  An object of the present invention is to provide a technology that makes it possible to balance the optimum load of three phases with a simple configuration while making it unnecessary to take a power outage measure during operation of a power supply system. To do.

  According to the power measuring device which is one of the aspects of the present invention, the power measuring device is installed in the distribution board for distributing the three-phase AC power, from the three-phase power at the power receiving point and the distribution board. A measurement unit that measures the single-phase power of each branch load that is branched, and a display that monitors the balance of each of the three phases based on the results measured by the measurement unit, and outputs and displays information about the operation status between the phases. And a section.

  Moreover, according to the power measurement system which is one aspect of the present invention, the power supply system that distributes the three-phase AC power by the bus duct system includes the power measurement device that measures the power at the power receiving point and the load branch point. A power measurement system, a first power measurement device that measures three-phase power at a power receiving point, a second power measurement device that measures single-phase power of a branch load, wired or wireless communication, or power line carrier Via communication, acquire the three-phase power of the receiving point and the single-phase power of the branch load measured in the first and second power measuring devices, and based on the acquired information, balance the three phases. And a display unit for monitoring and outputting and displaying information related to the operation status between the phases.

  According to the present invention, it is possible to balance the optimum load of the three phases with a simple configuration while making it unnecessary to take a power failure measure during operation of the power supply system.

It is a figure which shows a part of structure of the power supply system which has the electric power measuring apparatus which concerns on 1st Embodiment. It is a figure which shows the structural example of a phase switch. It is a figure which shows a part of structure of the power supply system which has the electric power measuring apparatus which concerns on 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
<First Embodiment>
FIG. 1 is a diagram illustrating a part of a configuration of a power supply system having a power measuring device according to the present embodiment. The distribution board 3 of the power supply system 10 shown in FIG. 1 has a circuit breaker (Molded Case Circuit Breaker, hereinafter referred to as MCCB) 4, 5, a power measuring device 1, and a phase switch 6. The three-phase AC power supplied from is divided to supply single-phase AC power to each load 20. In FIG. 1, only the structure regarding the method of monitoring the balance of the phase by the electric power measurement apparatus 1 which concerns on this embodiment is shown.

Of the distribution board 3, MCCB 4 is provided at the power receiving point. When an overcurrent flows from the power receiving point due to overload or short circuit, this is detected and the supply of power from the power system 2 is stopped. Let
The MCCB 5 is provided on the load 20 side, and when an overcurrent flows to the load 20 side due to an overload or the like, the MCCB 5 detects this and stops the supply of power to the load 20.

  The power measurement device 1 takes in information such as the MCCB 4 on / off information, the power receiving point and the voltage value and current value of each load 20, and calculates the three-phase power at the power receiving point and the single phase power of each load 20. Then, the power measuring apparatus 1 monitors the balance of each of the three phases based on the three-phase power at the power receiving point and the single-phase power of each load 20 obtained by calculation. The power measuring device 1 then provides information such as the amount of power used between phases (between RS, ST and TR) and how much room is available for the maximum allowable level in a balanced state. Is displayed. In the embodiment, these pieces of information are displayed on the phase capacity display 11 illustrated in FIG.

  The phase capacity indicator 11 in FIG. 1 outputs and displays information on the operation status between the phases by the LED display unit 12 and the capacity allowable level 13, and the user can see at a glance whether the phase is balanced. Can be discriminated by.

Specifically, the phase capacity indicator 11 displays the actual power consumption between the respective phases as a bar graph or the like, and displays which phase has a margin with respect to the maximum allowable level 13.
Ideally, the power levels between the phases are equal and the load between the phases is balanced and operated. Therefore, the power measuring apparatus 1 also monitors the difference ΔP between the maximum value and the minimum value among the power usage amounts between the phases. When the difference ΔP is less than the predetermined threshold, the power level balance between the phases is good, and the LED indicating that the state of the LED display unit 12 is “good” is turned on. When the difference ΔP is equal to or greater than a predetermined threshold, it is determined that the phase balance is lost, and the LED indicating the “alarm” state of the LED display unit 12 is turned on.

  The method of lighting the “good” or “alarm” LED of the LED display unit 12 is not limited to this. For example, the alarm to be lit may be switched from “good” to “alarm” when the power of the load circuit exceeds a predetermined level.

  The phase switch 6 in FIG. 1 is provided to distribute power to a predetermined phase among the three phases. For example, when the power measuring device 1 detects a phase balance failure in the power supply system 10 and the LED display unit 12 or the like outputs an indication to that effect, the phase switcher 6 switches the phase accordingly. I do. This will be described with reference to FIG.

  FIG. 2 is a diagram illustrating a configuration example of the phase switch 6. As shown in FIG. 2, the phase switch 6 distributes the input three-phase power to any one of the RS phase, the ST phase, and the TR phase by the fixed contact 61, the movable contact 62, and the cable wiring 63.

Specifically, the movable contact 62 is slid and the movable contact 62 is connected to the cable wiring 63 of any one of the three phases by switching the fixed contact 61 of each phase.
Note that the movable contact 62 can be configured to be slid to a phase where the amount of power used between phases is a minimum value by automatic control, for example, or the user can refer to the phase capacity indicator 11 of FIG. And it can also be set as the structure which performs the operation of switching to a desired phase manually.

  As described above, the phase capacity indicator 11 provided in the distribution board 3 in FIG. 1 allows the user to switch phases to the load by using the phase switch 6 in FIG. 2 while confirming the capacity status. By distributing the power, the load balance is adjusted to the optimum in the distribution board 3.

As described above, according to the present embodiment, in the power measuring device 1 provided in the distribution board 3, the three-phase power at the power receiving point and the single-phase power of each branch load 20 branched from the distribution board 3 are obtained. Measure and thereby monitor the balance of the three phases. While the power supply system 10 is in operation, it is possible to balance the phases with a simple configuration while making it unnecessary to take a power failure measure.
<Second Embodiment>
In the above embodiment, in the power supply system 10 that performs power distribution by the distribution board 3, the power measuring device 1 installed in the distribution board 3 monitors the phase balance, and if necessary, Switching phases. On the other hand, in the present embodiment, in the power supply system adopting the bus duct system, power measuring devices are arranged at each of the power receiving point and the branch load, and based on the information obtained by each power measuring device, the upper device Differ in that the balance of the phase is monitored.

  In the following, the method for monitoring the phase balance and switching the phases according to the present embodiment will be described focusing on the differences from the above embodiments. In the following description, the same components as those in the first embodiment will be described with the same reference numerals.

  FIG. 3 is a diagram showing a part of the configuration of a power supply system having the power measuring device according to the present embodiment. The power supply system 30 shown in FIG. 3 distributes the three-phase AC power supplied from the power system 2 by a bus duct system, and supplies single-phase AC power to each load.

The MCCB 4 is a circuit breaker provided at a power receiving point, and the operation thereof is the same as that of the above embodiment.
Power is distributed from the power receiving point to each load 20 through the bus duct 7. As shown in the configuration diagram D showing details in the vicinity of the junction between the bus duct and each load 20 in FIG. 3, the bus duct 7 houses the bus bar 21 therein. Four bus bars 21 are provided for three-phase four-wire (R-phase, S-phase, T-phase, and ground).

  The PIU 8 (8A, 8B) can be hot-plugged into and removed from the bus duct 7 in a plug-in manner, and a contact (not shown in FIG. 3) of the PIU 8 is stuck in the bus duct 7 and sandwiches the bus bar 21 in the bus duct 7 Take. In this way, electric power is supplied to the load wiring 22 of the PIU 8 through the bus duct 7.

The PIU 8 supplies power to the load 20 through the load wiring 22. The operation of the MCCB 5 on the load side installed in the PIU 8 is the same as in the above embodiment.
The power measurement system 40 according to the present embodiment includes a power measurement device (power measurement device 33 and power measurement device 9), a communication signal line 34, and a central monitoring device 80. The power measurement system 40 uses information held by the MCCB 4 and the PIU 8 constituting the power supply system 30 to monitor the phase balance in the power supply system 30 and switch phases when necessary.

The power measuring device 33 on the power reception point side takes in information such as the MCCB 4 on / off information and the voltage value and current value of the power reception point, and calculates the three-phase power at the power reception point.
The power measuring device 9 (9A, 9B) on the load 20 side takes in information such as a voltage value and a current value of the load 20 connected through the load wiring 22, and calculates single-phase power in each load 20. The power measuring device 9 transmits the power obtained by calculation to the power measuring device 33 on the power receiving side via the communication signal line 34.

  The power measuring device 33 on the power receiving point side transmits the three-phase power at the power receiving point measured in its own device and the single-phase power of the load 20 received from the power measuring device 9 on the load side to the upper central monitoring device 80. To do.

  The central monitoring device 80 monitors the phase balance of the entire power supply system 30 from the information transmitted from the power measuring device 33, that is, the three-phase power at the power receiving point and the single-phase power at each branch load. The specific monitoring performed by the central monitoring device 80 is the same as that performed by the power measurement device 1 of FIG. 1 in the above embodiment. Information such as the amount of power used for each phase of the PIU 8 recognized by the central monitoring device 80 and how much room is available for the maximum allowable level is transmitted to the PIU 8.

  Here, the PIU 8 can take two configurations depending on whether or not the phase capacity indicator 11 and the phase switch 6 in FIG. 2 are provided therein. In FIG. 3, the PIU 8 including the phase switch 6 is referred to as “type 1 PIU 8A”, and the PIU 8 not including the phase switch 6 is referred to as “type 2 PIU 8B”. In FIG. 3 and the following description, configurations having different functions in Type 1 and Type 2 are distinguished from each other with reference numerals A and B, respectively.

  The type 1 PIU 8A has a phase capacity indicator 11 and a phase switch 6 inside, and a power measuring device 9A is installed in the PIU 8A, and similarly to the power measuring device 1 of FIG. A container 11 is provided. The configuration and operation of the phase capacity indicator 11 are the same as those in the above embodiment.

  According to the information transmitted from the central monitoring device 80, the power measuring device 9 </ b> A determines which phase capacity indicator 11 has a margin between phases with respect to the power usage amount between each phase and the maximum allowable level, and the phase balance. Whether the condition is good or an alarm condition is output and displayed. In the case of receiving notification from the central monitoring device 80 that the phase balance has been detected, the phase switcher 6 switches the phases according to automatic control or user operation, as in the above embodiment. I do. The operation of the phase switch 6 is as described with reference to FIG. 2 in the above embodiment.

  The type 2 PIU 8B has a configuration in which the phase capacity indicator 11 and the phase switch 6 are not mounted, and the LED indicator 52 is provided in the load wiring 22B. In the PIU 8B, since the phase switch 6 is not mounted, the connection phase is fixedly determined for each load wiring 22B. As shown in FIG. 3, the distribution line that is actually divided by the PIU 8B is output from a power cable tap or an outlet, and the user can select which phase to use from a plurality of output circuits. It has become.

  About the LED indicator 52 provided in the load wiring 22B part, according to the information transmitted from the central monitoring apparatus 80, the LED indicator 52 corresponding to the phase with the most capacity among each phase is lighted.

  Thus, according to the power measurement system 40 according to the present embodiment, in the power supply system 30 that distributes power by the bus duct method, the same effect as the power measurement device 1 installed in the distribution board 3 is obtained. . That is, it is possible to balance the phases with a simple configuration while making it unnecessary to take a power failure measure during operation of the power supply system 30.

  In the above description, the communication between the power measuring devices 33 and 9 is performed by wired communication. However, the present invention is not limited to this, and information may be transmitted and received by wireless communication. . Or it can also be set as the structure which utilizes power line carrier communication.

  In the above description, the case where the central monitoring device 80 monitors the phase balance has been described. However, the present embodiment is not limited to this. For example, the power measuring device 33 on the power receiving side can be configured to have a monitoring function.

  The present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, all the constituent elements shown in the embodiments may be appropriately combined. Furthermore, constituent elements over different embodiments may be appropriately combined. It goes without saying that various modifications and applications are possible without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1 Electric power measurement apparatus 2 Electric power system 3 Distribution board 4, 5 Circuit breaker for wiring (MCCB)
6-phase switch 7 Bus duct 8 Plug-in unit (PIU)
DESCRIPTION OF SYMBOLS 9 Power measuring device 11 Phase capacity indicator 12 LED display part 13 Capacity tolerance level 10, 30 Power supply system 21 Bus bar 33 Power measuring device 34 Communication signal line 80 Central monitoring device

Claims (5)

A power measuring device installed in a distribution board that distributes three-phase AC power,
A measuring unit for measuring the three-phase power at the power receiving point and the single-phase power of each branch load branched from the distribution board;
Based on the measurement result of the measurement unit, the balance of each phase of the three phases is monitored, and the actual power consumption between each phase and how much each phase has the maximum allowable level is output and displayed. A display unit;
A power measuring device comprising: A distribution board having the power measuring device according to claim 1 ,
It has a switching part that switches the phase to distribute power to the load by selecting the connection phase from the three-phase power,
The switching unit switches the connection phase according to information on the operation status between the phases, or the actual power consumption between the phases and how much margin each phase has with respect to the maximum allowable level. Distribution board. In a power supply system that distributes three-phase AC power by a bus duct method, a power measurement system having a power measurement device that measures power at a power receiving point and a load branch point,
A first power measuring device that measures three-phase power at a power receiving point;
A second power measuring device for measuring the single-phase power of the branch load;
Based on the acquired information, acquire the three-phase power of the power receiving point and the single-phase power of the branch load measured by the first and second power measurement devices via wired or wireless communication or power line carrier communication. , A display unit that monitors the balance of each phase of the three phases and outputs and displays information on the operation status between each phase;
A power measurement system comprising: The power measurement system according to claim 3 , wherein the display unit outputs and displays an actual power consumption amount between the phases and how much each phase has a margin with respect to a maximum allowable level. In the power supply system having the power measurement system according to claim 3 or 4 ,
It is provided in a plug-in unit for branching load extraction that can be attached to and detached from the bus duct with a live line, and has a switching unit that switches a phase to be divided into loads by selecting a connection phase from three-phase power,
The switching unit switches a connection phase according to information displayed on a display unit of the power measurement system.