CN107546711B - Power plant system and control method of power plant system - Google Patents
Power plant system and control method of power plant system Download PDFInfo
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- CN107546711B CN107546711B CN201710334532.2A CN201710334532A CN107546711B CN 107546711 B CN107546711 B CN 107546711B CN 201710334532 A CN201710334532 A CN 201710334532A CN 107546711 B CN107546711 B CN 107546711B
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Abstract
Provided are a power plant system and a control method for the power plant system, which can realize a measure for an instantaneous voltage of a commercial power supply at low cost. The power plant system is configured to store in a memory, as a contact state, whether a contact of the electromagnetic contactor is on or off for each set period, and when an abnormality signal is input from the undervoltage relay, switch the contact of the electromagnetic contactor from off to on when the contact state stored in the memory is on, and keep the contact of the electromagnetic contactor in an off state when the contact state stored in the memory is off, based on the contact state stored in the memory.
Description
Technical Field
The present invention relates to a power plant system including a power plant driven by electric power supplied from a commercial power source, and a control method for the power plant system.
Background
Conventionally, when a power plant of a building is driven, a voltage of a commercial power supply introduced into the building is instantaneously dropped, so that an electromagnetic contactor connected to the power plant is changed from an excited state to a demagnetized state, and a contact of the electromagnetic contactor is switched from on to off, and as a result, power supply to the power plant is cut off.
Therefore, various techniques have been proposed for eliminating a failure caused by the occurrence of such an instantaneous low voltage of the commercial power supply (see, for example, patent documents 1 and 2). As a measure against the instantaneous voltage of the commercial power supply being low, a delayed release electromagnetic contactor is used as an electromagnetic contactor connected to the power plant or a battery is connected to the electromagnetic contactor.
[ patent document ]
[ patent document 1 ] Japanese patent application laid-open No. 2-232701
[ patent document 2 ] Japanese patent application laid-open No. Sho 63-43521
Disclosure of Invention
Problems to be solved by the invention
Here, in the conventional technology, as a measure against the instantaneous voltage of the commercial power supply being low, a delayed release type electromagnetic contactor is used as an electromagnetic contactor connected to the power plant or a battery is connected to the electromagnetic contactor, which leads to an increase in the cost of the entire power plant system. Therefore, a power plant system capable of realizing a countermeasure against an instantaneous voltage drop of a commercial power supply at low cost is required.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power plant system and a control method of the power plant system, which can realize a measure against an instantaneous voltage drop of a commercial power supply at low cost.
Means for solving the problems
The power plant system of the present invention has: a commercial power supply; a 1 st transformer and a 2 nd transformer connected to a commercial power supply; an undervoltage relay that outputs an abnormal signal when an input voltage input from a commercial power supply via the 2 nd transformer changes from a normal state to an abnormal state due to a voltage drop that generates the commercial power supply; an electromagnetic contactor that supplies power from a commercial power source to a power plant via a 1 st transformer when a contact is closed, and cuts off the power supply when the contact is open; and a control device that controls such that the contact of the electromagnetic contactor is on during driving of the power plant, the contacts of the electromagnetic contactor are opened during a stop of the power plant, and the control device stores whether the contacts of the electromagnetic contactor are opened or closed as a contact state in a memory at every set period, when an abnormal signal from the undervoltage relay is inputted, the control device controls the electromagnetic contactor according to the contact state stored in the memory, and when the contact state stored in the memory is on, the control device switches the contact of the electromagnetic contactor from off to on to drive the power equipment again, when the contact state stored in the memory is open, the contacts of the electromagnetic contactor are kept open and the power unit is kept stopped.
In addition, in the control method of a power plant system of the present invention, the power plant system includes: a commercial power supply; a 1 st transformer and a 2 nd transformer connected to a commercial power supply; an undervoltage relay that outputs an abnormal signal when an input voltage input from the commercial power supply via the 2 nd transformer changes from a normal state to an abnormal state due to a voltage drop that causes the commercial power supply; and an electromagnetic contactor that supplies electric power from a commercial power supply to a power plant via a 1 st transformer when a contact is closed and cuts off the electric power supply when the contact is opened, wherein the control method of the power plant system includes the steps of: controlling so that the contact of the electromagnetic contactor is on during driving of the power plant, the contact of the electromagnetic contactor is opened during a stop of the power equipment, and whether the contact of the electromagnetic contactor is turned on or off is stored in a memory as a contact state at every set period, when an abnormal signal from the undervoltage relay is outputted, the electromagnetic contactor is controlled according to the contact state stored in the memory, in the step of controlling the electromagnetic contactor, in the case where the contact state stored in the memory is on, the contact of the electromagnetic contactor is switched from off to on to cause the power unit to be driven again, when the contact state stored in the memory is open, the contacts of the electromagnetic contactor are kept open and the power unit is kept stopped.
Effects of the invention
According to the present invention, a power plant system and a control method of the power plant system are provided that can realize a measure against an instantaneous voltage drop of a commercial power supply at low cost.
Drawings
Fig. 1 is a configuration diagram showing a power plant system according to embodiment 1 of the present invention.
Fig. 2 is an explanatory diagram for explaining an operation of the undervoltage relay in fig. 1.
Fig. 3 is a flowchart showing a contact state storage process executed by the control apparatus of fig. 1.
Fig. 4 is a flowchart showing a contact control process executed by the control apparatus of fig. 1.
Description of the reference symbols
1 commercial power supply; 2, a 1 st transformer; 3, 2 nd transformer; 4 under-voltage relay; 5 a circuit breaker; 6 an electromagnetic contactor; 7 a control device; 8 power equipment.
Detailed Description
Next, a power plant system and a control method of the power plant system according to the present invention will be described with reference to the accompanying drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and redundant description thereof is omitted. The present invention can be applied to, for example, a power plant of a building to which electric power is supplied from a commercial power supply.
Embodiment mode 1
Fig. 1 is a configuration diagram showing a power plant system according to embodiment 1 of the present invention. The power plant system of fig. 1 includes a commercial power supply 1, a 1 st transformer 2 and a 2 nd transformer 3 connected to the commercial power supply 1, an undervoltage relay 4 connected to the 2 nd transformer 3, a breaker 5 connected to the 1 st transformer 2, an electromagnetic contactor 6 connected to the breaker 5, a control device 7, and a power plant 8 such as an air conditioner, a lighting apparatus, a drain/feed water pump, a fan, or the like connected to the electromagnetic contactor 6.
The commercial power supply 1 is, for example, a general commercial power supply having a voltage set to 6600V. The 1 st transformer 2 steps down the voltage input from the commercial power supply 1 to, for example, 220V, and inputs the stepped-down voltage to the breaker 5. The 2 nd transformer 3 steps down the voltage input from the commercial power supply 1 to 110V, for example, and inputs the stepped-down voltage to the undervoltage relay 4.
The undervoltage relay 4 is configured to detect an instantaneous voltage drop of the commercial power supply 1. The instantaneous voltage drop of the commercial power supply 1 may be, for example, a drop in the power supply voltage from a power company.
When the input voltage from the 2 nd transformer 3 is lower than the set voltage for the 1 st set time and then returns to the state of being equal to or higher than the set voltage, the undervoltage relay 4 transmits an abnormal signal to the control device 7 for the 2 nd set time. Specifically, the undervoltage relay 4 is configured such that the contact is opened when the input voltage is equal to or higher than the set voltage, and when the input voltage is returned to the state equal to or higher than the set voltage after the state in which the input voltage is lower than the set voltage continues for the 1 st set time period, the contact is closed during the 2 nd set time period, and an abnormal signal is transmitted.
The state in which the input voltage from the 2 nd transformer 3 is lower than the set voltage is referred to as an abnormal state, and the state in which the input voltage from the 2 nd transformer 3 is equal to or higher than the set voltage is referred to as a normal state.
Although the respective values of the set voltage, the 1 st set time, and the 2 nd set time can be appropriately designed, the respective values may be designed as follows, for example, in consideration of a case where the instantaneous voltage of the commercial power supply 1 is detected using the undervoltage relay 4. That is, the set voltage may be set to a value of, for example, 50% of the input voltage from the 2 nd transformer 3 when the commercial power supply 1 is normal. The 1 st set time may be set to, for example, 0.01 second. The 2 nd set time may be set to, for example, 1 second.
Next, the undervoltage relay 4 is further described with reference to fig. 2. Fig. 2 is an explanatory diagram for explaining an operation of the undervoltage relay 4 in fig. 1. Fig. 2 illustrates a case where the 1 st set time is 0.01 second and the 2 nd set time is 1 second.
Consider the following: when the voltage of commercial power supply 1 decreases, the input voltage from 2 nd transformer 3 switches from the normal state to the abnormal state, as shown in fig. 2, and the abnormal state continues for 0.01 second. In this case, the undervoltage relay 4 detects that the abnormal state of the input voltage continues for 0.01 second, and transmits an abnormal signal to the control device 7 for 1 second.
In this way, when the input voltage input from commercial power supply 1 via 2 nd transformer 3 changes from the normal state to the abnormal state due to the occurrence of the voltage drop of commercial power supply 1, undervoltage relay 4 outputs an abnormal signal to control device 7.
Returning to the description of fig. 1, the circuit breaker 5 is configured to cut off the supply of electric power from the commercial power supply 1 through the 1 st transformer 2 when an abnormality such as a short circuit occurs in the circuit, thereby preventing abnormal overheating, burnout, or the like of the wiring.
The electromagnetic contactor 6 is configured to be in an excited state and to be in a contact state when a voltage is applied to a coil (not shown) by the control of the control device 7, and to be in a demagnetized state and to be in a contact off state when the voltage is not applied to the coil.
When the contact is closed, the electromagnetic contactor 6 supplies electric power from the commercial power supply 1 to the power plant 8 via the 1 st transformer 2. On the other hand, when the contact is open, the electromagnetic contactor 6 cuts off the supply of electric power from the commercial power supply 1 to the power plant 8 via the 1 st transformer 2.
When the voltage of the commercial power supply 1 decreases, the electromagnetic contactor 6 cannot secure a voltage necessary to be applied to the coil to maintain the excited state, and thus the demagnetized state is achieved even when the voltage is applied to the coil by the control of the control device 7. That is, when the voltage of the commercial power supply 1 decreases, the electromagnetic contactor 6 is in a demagnetized state regardless of the control device 7, and as a result, the contact is opened.
The control device 7 is implemented by a processing circuit such as a CPU and a system LSI that executes a program stored in a memory, for example.
During the period when the power plant 8 is driven, since it is necessary to supply electric power to the power plant 8, the control device 7 controls the electromagnetic contactor 6 so that the contact is closed. On the other hand, during the period in which the power plant 8 is stopped, since the power supply to the power plant 8 is not necessary, the control device 7 controls so that the contacts of the electromagnetic contactor 6 are opened.
The control device 7 executes the following contact state storage processing for each set cycle: the contact state stored in the memory is rewritten and updated by storing whether the contact of the electromagnetic contactor 6 is on or off as the contact state in the memory (not shown). The value of the set period can be appropriately designed, and may be set to 10 seconds, for example.
When the abnormal signal is input from the undervoltage relay 4, the control device 7 determines that an instantaneous voltage drop of the commercial power supply 1 occurs, and executes a contact control process of controlling the contacts of the electromagnetic contactor 6 according to the contact state of the electromagnetic contactor 6 stored in the memory.
The control device 7 may be configured to monitor the driving state of the power plant 8 by transmitting information to the power plant 8.
Next, a contact state storage process executed by the control device 7 will be described with reference to the flowchart of fig. 3. Fig. 3 is a flowchart showing a contact state storage process executed by the control device 7 of fig. 1. The processing of the flowchart of fig. 3 is executed for each set cycle.
In step S11, the control device 7 stores and updates the current contact state of the electromagnetic contactor 6 in the memory, and the series of processes ends.
In this way, the control device 7 can monitor the latest contact state of the electromagnetic contactor 6 for each set period by storing the current contact state of the electromagnetic contactor 6 in the memory. Further, since the power plant 8 is driven when the contact of the electromagnetic contactor 6 is on and the power plant 8 is stopped when the contact of the electromagnetic contactor 6 is off, the control device 7 can grasp whether the power plant 8 is being driven or stopped as the operating state of the power plant 8 by storing the contact state of the electromagnetic contactor 6 in the memory.
Next, a contact point control process executed by the control device 7 will be described with reference to fig. 4. Fig. 4 is a flowchart showing a contact control process executed by the control device 7 of fig. 1.
In step S21, control device 7 determines whether or not an abnormality signal is input from undervoltage relay 4.
When the abnormality signal is input from the undervoltage relay 4, the control device 7 determines that an instantaneous voltage drop of the commercial power supply 1 occurs, and the process proceeds to step S22. On the other hand, when the abnormality signal is not input from the undervoltage relay 4, the control device 7 determines that the instantaneous voltage drop of the commercial power supply 1 does not occur, and executes the process of step S21 again.
When the instantaneous voltage of the commercial power supply 1 is low, the electromagnetic contactor 6 changes to a demagnetized state even when in an excited state, and as a result, the contact is opened.
In step S22, the control device 7 determines whether or not the contact state of the electromagnetic contactor 6 stored in the memory at the present time is on.
When the contact state of the electromagnetic contactor 6 stored in the memory is on, the process proceeds to step S23. On the other hand, when the contact state of the electromagnetic contactor 6 stored in the memory is open, the process proceeds to step S24.
In step S23, since the contact state of the electromagnetic contactor 6 stored in the memory is on, the control device 7 determines that the power plant 8 is being driven before the voltage of the commercial power supply 1 decreases, and switches the contact of the electromagnetic contactor 6 from off to on, thereby driving the power plant 8 again, and the series of processes ends. That is, the power plant 8 that was being driven before the voltage drop of the commercial power supply 1 occurred is driven again as the voltage drop of the commercial power supply 1 that occurred instantaneously is recovered.
In step S24, since the contact state of the electromagnetic contactor 6 stored in the memory is off, the control device 7 determines that the power plant 8 is stopped before the voltage of the commercial power supply 1 decreases and keeps the contact of the electromagnetic contactor 6 in the off state, thereby keeping the power plant 8 in the stopped state and ending the series of processes. That is, the power plant 8 that was stopped before the voltage drop of the commercial power supply 1 occurred is driven without being recovered from the voltage drop of the commercial power supply 1 that occurred instantaneously.
In this way, when the voltage of the commercial power supply 1 is low, the control device 7 controls the contact of the electromagnetic contactor 6 based on the contact state of the electromagnetic contactor 6 before the voltage of the commercial power supply 1 is low, that is, the contact state of the electromagnetic contactor 6 stored in the memory. Therefore, the power plant 8 that was stopped before the voltage drop of the commercial power supply 1 occurred can be prevented from being unnecessarily driven.
In embodiment 1, the case where the power plant system is configured by providing 1 electromagnetic contactor 6 and 1 control device 7 which correspond to each other one by one is exemplified, but the present invention is not limited to this, and the power plant system may be configured by providing N groups (N is an integer of 2 or more) of groups including 1 electromagnetic contactor 6 and 1 control device 7 which correspond to each other one by one.
Further, the power plant system may be configured by providing N electromagnetic contactors 6 and 1 control device 7. In this case, the control device 7 is configured to store the contact state as the contact state of whether the contact is on or off for each electromagnetic contactor 6 in the memory, and to independently control each electromagnetic contactor 6 in accordance with the contact state stored in the memory when the abnormality signal from the undervoltage relay 4 is input.
According to embodiment 1 described above, whether the contact of the electromagnetic contactor is on or off is stored in the memory as the contact state for each set period, and when an abnormal signal from the undervoltage relay is input, the contact of the electromagnetic contactor is switched from off to on if the contact state stored in the memory is on, and the contact of the electromagnetic contactor is kept off if the contact state stored in the memory is off, based on the contact state stored in the memory.
When a countermeasure against an instantaneous voltage drop of the commercial power supply is taken in the power plant system, by studying the control of the electromagnetic contactor by the control device as described above, it is no longer necessary to use a delay release type electromagnetic contactor or connect a battery to the electromagnetic contactor as in the conventional art, and as a result, it is possible to take measures against an instantaneous voltage drop of the commercial power supply at low cost.
In addition, in the above configuration, it is possible to prevent wasteful driving of the power plant that was stopped before the voltage drop of the commercial power supply occurred.
Claims (2)
1. A power plant system, wherein the power plant system has:
a commercial power supply;
a 1 st transformer and a 2 nd transformer connected to the commercial power supply;
an undervoltage relay that outputs an abnormal signal when an input voltage input from the commercial power supply via the 2 nd transformer changes from a normal state to an abnormal state due to a voltage drop of the commercial power supply;
an electromagnetic contactor that supplies power from the commercial power supply to a power plant via the 1 st transformer when a contact is closed, and cuts off the power supply when the contact is open; and
a control device that controls the electromagnetic contactor such that the contact of the electromagnetic contactor is on while the power plant is being driven and the contact of the electromagnetic contactor is off while the power plant is stopped, stores the contact of the electromagnetic contactor as a contact state in a memory at each set cycle, and controls the electromagnetic contactor according to the contact state stored in the memory when the abnormality signal from the undervoltage relay is input,
the control device switches the contact of the electromagnetic contactor from off to on to drive the power plant again when the contact state stored in the memory is on, and keeps the contact of the electromagnetic contactor off and stops the power plant when the contact state stored in the memory is off.
2. A method of controlling a power plant system,
the power plant system has:
a commercial power supply;
a 1 st transformer and a 2 nd transformer connected to the commercial power supply;
an undervoltage relay that outputs an abnormal signal when an input voltage input from the commercial power supply via the 2 nd transformer changes from a normal state to an abnormal state due to a voltage drop of the commercial power supply; and
an electromagnetic contactor that supplies electric power from the commercial power supply to a power plant via the 1 st transformer when a contact is closed and cuts off the electric power supply when the contact is opened,
the control method of the power equipment system comprises the following steps:
controlling the electromagnetic contactor such that the contact of the electromagnetic contactor is on while the power plant is driven and the contact of the electromagnetic contactor is off while the power plant is stopped, storing the contact of the electromagnetic contactor as a contact state in a memory as whether the contact of the electromagnetic contactor is on or off for each set period, and controlling the electromagnetic contactor based on the contact state stored in the memory when the abnormality signal from the undervoltage relay is output,
in the step of controlling the electromagnetic contactor, when the contact state stored in the memory is on, the contact of the electromagnetic contactor is switched from off to on to drive the power plant again, and when the contact state stored in the memory is off, the contact of the electromagnetic contactor is kept off to stop the power plant.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016-128700 | 2016-06-29 | ||
| JP2016128700A JP6415485B2 (en) | 2016-06-29 | 2016-06-29 | Power equipment system and control method of power equipment system |
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| Publication Number | Publication Date |
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| CN107546711A CN107546711A (en) | 2018-01-05 |
| CN107546711B true CN107546711B (en) | 2019-12-24 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201710334532.2A Active CN107546711B (en) | 2016-06-29 | 2017-05-12 | Power plant system and control method of power plant system |
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| JP (1) | JP6415485B2 (en) |
| CN (1) | CN107546711B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000193686A (en) * | 1998-12-25 | 2000-07-14 | Densei Lambda Kk | Voltage detection method detecting abnormality of ac voltage |
| CN1745504A (en) * | 2003-01-28 | 2006-03-08 | Abb服务有限公司 | A low-voltage circuit breaker comprising an interface unit |
| CN101981781A (en) * | 2008-02-04 | 2011-02-23 | 美国电力转换有限公司 | Automatic battery reconnection |
| CN204103447U (en) * | 2014-09-19 | 2015-01-14 | 常熟开关制造有限公司(原常熟开关厂） | A kind of undervoltage protection device |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01194222A (en) * | 1988-01-28 | 1989-08-04 | Daido Steel Co Ltd | Power source switching equipment |
| JPH0568340A (en) * | 1991-06-10 | 1993-03-19 | Mitsubishi Electric Corp | Conduction controlling device |
| JP2007189848A (en) * | 2006-01-16 | 2007-07-26 | Hitachi Ltd | Automatic power supply control system |
-
2016
- 2016-06-29 JP JP2016128700A patent/JP6415485B2/en active Active
-
2017
- 2017-05-12 CN CN201710334532.2A patent/CN107546711B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000193686A (en) * | 1998-12-25 | 2000-07-14 | Densei Lambda Kk | Voltage detection method detecting abnormality of ac voltage |
| CN1745504A (en) * | 2003-01-28 | 2006-03-08 | Abb服务有限公司 | A low-voltage circuit breaker comprising an interface unit |
| CN101981781A (en) * | 2008-02-04 | 2011-02-23 | 美国电力转换有限公司 | Automatic battery reconnection |
| CN204103447U (en) * | 2014-09-19 | 2015-01-14 | 常熟开关制造有限公司(原常熟开关厂） | A kind of undervoltage protection device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107546711A (en) | 2018-01-05 |
| JP6415485B2 (en) | 2018-10-31 |
| JP2018007353A (en) | 2018-01-11 |
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Address after: Tokyo, Japan Patentee after: Mitsubishi Electric Building Solutions Co.,Ltd. Address before: Tokyo, Japan Patentee before: MITSUBISHI ELECTRIC BUILDING TECHNO-SERVICE Co.,Ltd. |