Power control device

Patent metadata

Field	Value
Publication number	US-9479010-B2
Application number	US-201314397382-A
Country	US
Kind code	B2
Filing date	May 27, 2013
Priority date	Jun 18, 2012
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

A power control device is provided which can execute self-sustaining operation only when conditions for allowing the self-sustaining operation are satisfied reliably, so as to supply AC power to a power load connected with a power system before the self-sustaining operation.
In a case where an instruction to change the power control device into the self-sustaining operation state is accepted, the inverter is connected with the loads by the disconnection relay and the self-sustaining operation is started when voltage to be applied to a wiring portion between the disconnection relay and the earth leakage breaker is not detected, when current flowing between the main breaker and the power system is not detected and when a contact signal indicative of the open/close state of the main breaker indicates an open state. Moreover, the inverter is disconnected from the power system by the disconnection relay and the self-sustaining operation is stopped when the power control device is in the self-sustaining operation state in addition to that current flowing to or from the power system is detected or to that a contact signal indicative of the open/close state of the main breaker indicates a close state.

First claim

The invention claimed is:

1. A power control device, comprising:
an inverter that converts DC power into AC power;
a control unit that performs control so that AC power converted by the inverter is supplied, in linkage with a power system, to a power load which is to be supplied with electric power from the power system via a breaker and a current detector;
a disconnection relay for disconnecting the inverter from the power system;
a take-in unit that takes in a contact signal indicative of an open/close state of the breaker; and
a voltage detector that detects voltage at the power system side of a circuit to be disconnected by the disconnection relay,
wherein the control unit includes:
a storage unit in which whether the power control device is in a predetermined operating state or not is stored;
a first determination unit that determines whether the voltage detector has detected voltage or not;
a second determination unit that determines whether the current detector has detected current or not; and
an acceptance unit that accepts an instruction to put the power control device into the predetermined operating state when an information that the power control device is not in the predetermined operating state is stored in the storage unit,

wherein the control unit causes the disconnection relay to connect the inverter with the power load and stores, in the storage unit, an information that the power control device is in the predetermined operating state, in a case where the acceptance unit accepts the instruction, where the first determination unit and the second determination unit determine that voltage and current have not been detected and where a contact signal taken in by the take-in unit indicates an open state.

2. The power control device according to claim 1 ,
wherein the control unit includes a signal acceptance unit that accepts a predetermined signal in the case where the acceptance unit accepts the instruction, where the first determination unit and the second determination unit determine that voltage and current have not been detected and where a contact signal taken in by the take-in unit indicates an open state,
wherein the control unit connects the inverter with the power load when the signal acceptance unit accepts the predetermined signal.

3. The power control device according to claim 1 ,
wherein the control unit causes the disconnection relay to disconnect the inverter from the power system and stores, in the storage unit, an information that the power control device is not in the predetermined operating state, when an information that the power control device is in the predetermined operating state is stored in the storage unit in addition to that the second determination unit determines that current has been detected or to that a contact signal taken in by the take-in unit indicates a close state.

4. The power control device according to claim 1 ,
wherein the breaker is connected in series with another breaker.

5. The power control device according to claim 1 ,
wherein a relay switch is interposed between the breaker and the power load,
wherein the relay switch is turned on by control voltage applied from the power system via the breaker and a contact, which is turned on when the breaker is in a close state.

6. The power control device according to claim 1 ,
wherein the power system is connected with a second voltage detector,
wherein the control unit includes a display unit that makes a predetermined display when the second voltage detector detects a predetermined voltage.

7. The power control device according to claim 1 ,
wherein the breaker is provided in a panel board having a cover,
wherein the control unit includes a detection unit that detects that the cover has been opened,
wherein the control unit causes the disconnection relay to disconnect the inverter from the power system and stores, in the storage unit, an information that the power control device is not in the predetermined operating state, in a case where an information that the power control device is in the predetermined operating state is stored in the storage unit and where the detection unit detects that the cover has been opened.

Assignees

• Tsubakimoto Chain Co

Inventors

• Uehira Makoto
• Koyama Shingo

Classifications

• H02J3/388

  Arrangements for the handling of islanding, e.g. for disconnection or for avoiding the disconnection of power · CPC title

• H02H3/04

  with warning or supervision in addition to disconnection, e.g. for indicating that protective apparatus has functioned {(watching of pilot wires H02H1/0084; protection of protective arrangements H02H7/008; indication of the state of electronic switches H03K17/18)} · CPC title

• H01H2300/018

  Application transfer; between utility and emergency power supply · CPC title

• H02M7/44

  by static converters · CPC title

• H02M7/53871

  with automatic control of output voltage or current · CPC title