JPH0575924U - Load input device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a load applying device capable of performing load application without causing an instantaneous power failure to the load during operation, and extending the life of the load applying relay. To aim. [Configuration] Loads L _{1 to} L _n parallel from the power supply device 10
In load application device comprising a relay contact X _a1 to X _an, inserted into the power supply circuit to the corresponding detects the load which is shutdown from the presence or absence of current by monitoring the current flowing in the power supply circuit to the respective load It has a control circuit 20 for turning off the relay of the power supply circuit, and this control circuit is characterized by turning on the corresponding relay at a fixed time interval and sequentially activating it when the load which has stopped operation is restarted.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a load input device including a relay contact inserted in a power supply circuit from a power supply device to parallel loads.

[0002]

[Prior Art]

 FIG. 3A shows an example of this type of load input device. In the figure, 10 is a power supply device, such as an inverter device, X_a1~ X_anIs the load input relay X shown in FIG.₁~ X_nContact, 11 is a relay control circuit, SW₁~ SW _n Is the load side switch, L₁~ L_nIs, for example, an AC motor of a refrigerator compressor. The relay control circuit is equipped with a timer, relay X₁~ X_nThe ON command and the OF command for the are sent at fixed time intervals.

In this configuration, when the power supply device 10 has a maximum capacity, such as an inverter device, an in-house power generation device, or a battery, when the AC motors L _{1 to} L _n are started, it is shown in FIG. are sequentially activated by the closing child contact X _a1 to X _an, the relay at predetermined time intervals so as to prevent power overload by rush current.

[0004] Then, if after the activation of all the AC motor, for example, one of the load-side switch of the AC motor L ₁ (e.g., thermal switch) SW ₁ is the AC motor L ₁ and OFF is sealed driving holiday, this AC When the electric motor L ₁ is restarted, the AC electric motors L _{2 to} L _n are sequentially stopped, and then the sequential start is performed.

[0005]

[Problems to be solved by the device]

 In this way, when restarting a suspended load, power supply to all operating loads is temporarily cut off, so that a momentary power failure will occur at each restart and the relay contact X _a1 ~ X_anThere was a problem that the frequency of opening and closing was high and the contact life was shortened.

The present invention has been made in order to solve this problem. It is possible to apply a load without causing an instantaneous blackout to the load during operation, and to extend the life of the load applying relay. It is an object of the present invention to provide a load input device capable of performing the above.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a load input device having a relay contact inserted in a power supply circuit from a power supply device to each load in parallel, and monitors the current flowing in the power supply circuit to each load to monitor the current flow. There is a control circuit that detects a load that has stopped operation from the presence or absence and turns off the relay of the corresponding power supply circuit.This control circuit turns on the corresponding relay at a certain time interval when the load that has stopped operation is restarted. Then, it is configured to be sequentially activated.

[0008]

[Action]

 According to the present invention, when the current flowing through the power supply circuit to the load is not detected, the relay in the power supply circuit is opened, and when the load is turned on again, the opened relays are sequentially closed.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1A, CT₁~ CT_nAre current detectors, each of which is an AC motor L₁~ L_nThe current flowing to is detected. Current detector CT₁~ CT_nAs shown in FIG. 1B, the detection signal of is input to a control circuit 20 composed of a microcomputer CPU, and the control circuit 20 follows the control flow shown in FIG.₁~ X _n To control.

Next, the operation of this device will be described with reference to the control flow shown in FIG.

(1) When starting the AC motors L _{1 to} L _n , the CPU 20 outputs ON commands to the relays X _{1 to} X _n at regular time intervals to sequentially start the relays X _{1 to} X _n .

(2) After starting all the AC motors L _{1 to} L _n , the CPU 20 cyclically monitors the presence / absence (H / L) of the detection signals of the current detectors CT ₁ to CT _n .

(3) For example, AC motor L₁Load side switch (eg thermal switch) SW ₁ When is turned off, AC motor L₁Since there is no current flowing to the current detector CT₁Detection signal becomes "L" level, and the CPU 20 causes the load side switch SW ₁ Is determined to be OFF, relay X₁OFF command is given to contact X_a1To open the circuit.

(4) The relays that are turned off are stored in the CPU 20, and when the relays that are turned off are reclosed, the CPU 20 gives an ON command to these relays at regular time intervals to stop the operation. Restart the AC motors that had been started by sequentially starting.

As described above, in the present embodiment, when the AC motor is reclosed, the AC motors are always injected one by one, so that the output current from the power supply device 10 must exceed the rated output current plus the rush current for one unit. Therefore, there is no risk of overloading the power supply, and the power supply device 10 can operate a larger number of loads than before.

Further, in the present embodiment, at the time of restarting, only the load that has been suspended from operation is started, and not the full load as in the conventional case. Therefore, the above-mentioned instantaneous blackout is applied to the load. There is no fear.

Further, since the relays X _{1 to} X _n are opened in a non-current state, the degree of wear of the relay contacts is lower than in the conventional case, and the life of the relays X _{1 to} X _n is extended accordingly.

[0019]

[Effects of the Invention] As described above, according to the present invention, when the load is turned on, the power supply to other loads that are in operation is not interrupted for a while, and only the load to be turned on is sequentially activated. It can be turned on without the fear of a momentary power failure, and the life of the load closing relay can be extended compared to the conventional case.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a control flow in the above embodiment.

FIG. 3 is a circuit diagram of a conventional load applying device.

FIG. 4 is a diagram showing a relay insertion sequence and a current amount in the above conventional example.

[Explanation of symbols]

10 power supply 20 controller L ₁ ~L _n load X ₁ to X _n relay X _a1 to X _an, relay contacts CT ₁ to CT _n current detector SW ₁ to SW _n load switch

Claims (1)

[Scope of utility model registration request] 1. A load application device having a relay contact inserted in a power supply circuit to a load from a power supply device connected in parallel, monitoring the current flowing in the power supply circuit to each load and suspending operation depending on the presence or absence of the current. It has a control circuit that detects the load and turns off the relay of the corresponding power supply circuit, and this control circuit turns on the corresponding relay at a fixed time interval to restart the load after the operation is stopped. A load input device characterized in that