KR100790521B1 - Apparatus for compensating elctricity abnormality - Google Patents

Abstract

An apparatus for compensating electricity abnormality is provided to efficiently compensate the electricity abnormality and extend life of the electrical instruments by making users select power recovery time after a temporary interruption of electric power. An apparatus for compensating electricity abnormality includes a phase detecting part(117), a voltage detecting part(116), a voltage compensating unit, and a control part(124). The phase detecting part detects a phase of an input voltage by being connected with an input diverging cable diverged from an input cable and stores a zero point. The voltage detecting part detects an input voltage by being connected with the input diverging cable diverged from the input cable and stores the currently inputted voltage. The voltage compensating unit generates a compensating voltage and outputs the compensating voltage through a power output terminal. The control part intercepts a bypass switch and controls the voltage compensating unit so as to output the compensating voltage according to a signal received from the phase detecting part and the voltage detecting part.

Description

Apparatus for compensating elctricity abnormality

1 is a typical power quality accident type

2 is a block diagram of a conventional power failure compensation device.

3 is an overall configuration diagram of a power failure compensation device according to the present invention.

4 is an internal configuration diagram of a control unit.

5 is a diagram illustrating an internal configuration of a DC / AC inverter.

Figure 6 is a flow chart illustrating the operation of the power failure compensation device according to the present invention.

The present invention relates to a power supply abnormality compensation device for outputting a compensation voltage in order to protect the electrical equipment in the case of voltage drop, voltage rise, instantaneous power failure.

1 illustrates a typical type of power quality incident.

(a) is a voltage sag or dip. Duration is less than 1 minute and 0.1 to 0.9 p.u. of rated voltage. It is a phenomenon having a magnitude of a degree. If the duration is over 1 minute, it is called under-voltage.

(b) is the voltage swell. Duration of less than 1 minute and 1.1 to 1.8 p.u. of rated voltage. It is a phenomenon having a magnitude of a degree. If the duration exceeds one minute, it is called over-voltage.

(c) is instantaneous power interruption (or interruption). Supply voltage or load current is 0.1p.u. The phenomenon that decreases to less than 0.5 seconds is called instantaneous power failure, and less than 1 minute is called short-term power failure.

Such power quality incidents are a big challenge for many manufacturers of electrical equipment.

Conventionally, there is a compensation device for such a power quality accident. 2 is a block diagram of a conventional representative low voltage detection and compensation device. The thick solid line shows normal current flow, the thin solid line shows current flow when compensating by low voltage detection, and the dotted line shows the flow of control signal of the controller.

Usually, the power Vin input through the power input terminal IN is output to the power output terminal OUT along the output line 14 through the bypass switch 10 along the input line 12. At this time, the input voltage is always monitored by the voltage detector 16 through the input branch line 13 branched from the input line 12. In addition, AC current is dropped by the transformer 18 through the output branch line 15 branched from the output line 14 (eg, 13V AC), and converted to DC by the AC / DC converter 20 (eg, 48VDC). ). The converted DC voltage is charged in the capacitor 22. Therefore, the power corresponding to the capacity (for example, 12.4F) of the capacitor 22 is usually charged in the capacitor 22.

In this state, when a low voltage is detected by the voltage detector 16 (e.g., when detecting 185V or less when Vin = 220V), the controller 24 cuts off the bypass switch 10 and at the same time the capacitor 22 Control for discharging the electricity charged in ()). This is done by manipulating the DC / AC inverter 28 connected to the discharge side line 26 of the capacitor 22. When the DC / AC inverter 28 is operated by the controller 24, the DC electricity charged in the capacitor 22 is discharged and converted into AC in the inverter 28 (eg, 13 VAC). The converted AC electricity is then boosted to the rated voltage in the transformer 18 (eg 220VAC) and output through the output terminal OUT as the compensated voltage Vcomp.

Such a conventional low voltage compensation device detects only a case of an instantaneous low voltage but is defenseless against overvoltage, and there is a problem in that an excessive surge voltage is generated when a momentary power failure or a power recovery situation occurs. In addition, since it always outputs the rated voltage (220V) regardless of power fluctuations before and after the occurrence of a low voltage situation, there is no fundamental solution to power quality accidents.

Accordingly, the present inventors have developed a power failure compensation device according to the present invention in order to solve the problems of the prior art. The power failure compensation device according to the present invention detects not only the input voltage but also the phase value, stores the zero point of the input voltage, monitors both the upper and lower ranges of the voltage, and the zero of the stored input voltage at the time of recovery after an instantaneous power failure. Provided is a configuration for suppressing reactive power by performing restoration in synchronization with the point.

Power failure compensation device according to the present invention,

A phase detector connected to an input branch line branched from the input line to detect the phase of the input voltage and storing a zero point, and a current detector connected to an input branch line branched from the input line to detect the input voltage When voltage abnormality is generated according to the voltage compensation unit, a voltage compensating means for generating a compensation voltage and outputting the voltage through the power output stage when it is determined that the voltage abnormality has occurred in the voltage detection unit, and a signal received by the phase detection unit and the voltage detection unit. And a control unit for blocking the bypass switch and controlling the voltage compensation means to output a compensation voltage.

Hereinafter, with reference to the drawings will be described in more detail the configuration and operation of the present invention.

3 is an overall configuration diagram of a power failure compensation device according to the present invention.

The thick solid line shows the current flow in normal operation, the thin solid line shows the flow of current in operation of the compensator, and the dotted line shows the flow of control signal of the controller. Similar to the conventional apparatus of FIG. 2, power input through the power input terminal IN is normally connected to the power output terminal OUT along the output line 114 through the bypass switch 110 along the input line 112. Will print The bypass switch 110 may be implemented using a mechanical switch (relay, etc.) or an electronic device (SCR, IGBT, FET, etc.).

The phase detector 117 and the voltage detector 116 are connected to the input branch line 113 branched from the input line 112. These monitor the phase and voltage of the input voltage at all times. The controller 124 operates (described later with reference to FIG. 4) by the detection results of the phase detector 117 and the voltage detector 116. The voltage detector 116 is capable of setting the upper and lower limits of the input voltage.

On the other hand, AC current through the input branch line 113 is input to the voltage compensation means. This will be described. By the operation of the capacitor charging unit 120 is converted into DC (for example, 12VDC) is charged in the capacitor 122. In this regard, the capacitor charging unit 120 of the present invention performs a function similar to that of the AC / DC converter 20 of FIG. 2. The DC electricity charged in the capacitor 122 is discharged from the capacitor 122 by the control of the DC / AC inverter 128 of the control unit 124 and is converted back to AC in the DC / AC inverter 128 to transformer 118 Is applied to. At the output terminal of the transformer 118, a dummy resistor is connected to prevent a harmonic phenomenon because a minimum current flows normally.

As described above, the phase and the voltage are detected from the input voltage flowing through the input line 112, and a part of the input voltage is branched so that a constant voltage is always applied to the transformer 118.

If an abnormality occurs in the input voltage (voltage drop, voltage rise, instantaneous power failure, etc.), the controller 124 shuts down the bypass switch 110 and controls the DC / AC inverter 128 to enter the compensation mode. The compensation voltage 115 output from the transformer 118 is output from the output terminal OUT. The configuration and operation of the control unit 124 will be described separately.

4 shows the configuration of the control unit 124. There is a phase processing unit 201 for processing the phase signal output from the phase detection unit 117 of FIG. 3 and a phase value storage unit 203 for storing the phase value. The phase value storage unit 203 stores a zero crossing point of the voltage currently being input.

There is an input voltage monitoring unit 205 for monitoring the voltage detected by the voltage detection unit 116 in FIG. This is operated in conjunction with the input voltage value storage unit 207. The input voltage value storage unit 207 stores the input voltage value currently being input. As mentioned above, the input voltage monitoring unit 205 monitors whether the input voltage falls within the upper and lower limits. This is the primary difference from the conventional compensator (in the past, only the lower limit of the input voltage was monitored). The user can set the upper and lower allowable range of the input voltage.

The reason for storing the input voltage in the input voltage value storage unit 207 is that in the power failure compensation device of the present invention, when the compensation voltage is outputted at the time of power failure, the rated voltage is irrespective of the actual input voltage inputted just before. The voltage input from the system immediately before the power failure occurs is stored, and the voltage value is output as it is as a compensation voltage. By doing so, it does not adversely affect various electrical apparatuses using the power failure compensation device according to the present invention (as long as the input voltage is within the allowable range, the constant voltage is always inputted rather than the changed voltage being input into the electrical apparatus. Of course).

On the other hand, in another embodiment, in conjunction with the input voltage value storage unit 207, a memory capable of storing the variation of the input voltage and means for outputting the stored value can be provided. Of course, this memory may be part of the input voltage value storage unit 207, or may be a separate memory device. By storing the change of the input voltage in real time or intermittently, and outputting or monitoring the stored value, it is possible to monitor the change of the input power while continuously operating the electric equipment. Since this becomes important management data for the operator of the electrical equipment, it will be possible to further enhance the effect of the power failure compensation device of the present invention. The means for outputting the input voltage stored value may be included in the controller, but of course it may be installed as a separate single component.

As another embodiment, a means for storing and monitoring the history of the compensation action of the power failure compensation device according to the present invention together with the storage and monitoring of the variation of the input voltage may be further included. This can be achieved by storing and statistically processing the fluctuation value and the fluctuation time of the input voltage, and the function and compensation voltage value of the control unit operated corresponding thereto.

The bypass switch operation unit 209 is included in the control unit 124. This is to cut off the bypass switch 110 of FIG. 3 and output the compensation voltage to the output terminal when a power failure occurs as a result of monitoring of the input voltage monitoring unit 205. The inverter operation unit 211 controls the DC / AC inverter 128 to cause the transformer 118 to output the compensation voltage. The main structure of this inverter operation part 211 is as FIG. That is, the inverter output voltage control unit 213 for controlling the DC / AC inverter 128 by controlling the output voltage of the inverter when there is an abnormality in the voltage monitored by the input voltage monitoring unit 205 of the control unit 124, The capacitor charge amount detecting unit 215 detects the charge amount of the capacitor discharged to the DC / AC inverter 128 and informs the charge amount detected by the input voltage monitoring unit 205.

The operation of the power failure compensation device according to the present invention configured as described above will be described with reference to FIG.

Prior to the description of Figure 6, the function of the power failure compensation device according to the present invention will be described.

1) When the input voltage exceeds the set upper and lower limit ranges-In this case, the power failure compensation device according to the present invention controls to output the rated voltage as the compensation voltage after the bypass switch is cut off.

2) Instantaneous power failure-During instantaneous power failure, the bypass switch is cut off and the compensation voltage is output to the output terminal. When the power supply returns after instantaneous power failure (recovery), the control unit delays the recovery time of the bypass switch so as to be synchronized with the zero crossing point stored in the phase value storage unit. Therefore, since the bypass switch is returned at the zero point of the recovery time, the surge voltage is not generated at all, and thus reactive power can be suppressed. At the time of restoration, the output voltage is replaced with a new value other than the value stored in the input voltage value storage section. In this case, the soft-up process is used to flexibly replace the new output voltage so that the voltage value does not change suddenly.

The operation of the power failure compensation device according to the present invention will now be described with reference to FIG. 6. As shown in Figs. 3 and 4, the phase of the input voltage is detected (1100) and the zero crossing point is stored (1150). The voltage of the input voltage is detected (1200) and the input voltage value is stored (1250). It is determined whether the detected voltage is within a setting range (1300). If it is determined that the input voltage is within the set range and is not instantaneous power failure (1450), the state is in a normal state and thus the stored input voltage value is maintained and the voltage value is output from the output terminal (1800).

The following describes the power failure state, that is, the case out of the setting range and instantaneous power failure. If it is determined to be out of the setting range in step 1300 of determining whether it is within the setting range, the non-Instantaneous power failure cuts off the bypass switch (1500), and outputs a rated voltage as a compensation voltage (1600). The output of the compensation voltage is made by the voltage adjusting action of the DC / AC inverter 128 by the action of the control unit 124 as shown in FIGS. 3 and 5. In this state, the phase and voltage of the input voltage are continuously monitored (1700).

Next, when an instantaneous power failure state is detected in any state (1400 and 1450), the bypass switch is shut off (1900) and the stored output voltage value is maintained as the compensation voltage (2000). It is checked whether the device recovers within a predetermined time after the instantaneous power failure (2100). If the power is not restored within a predetermined time, the system is blocked (2600) to protect the electric device. If it is restored within a predetermined time, the bypass switch waits until the shortest zero point is reached from the stored zero point to synchronize the zero point stored in the phase value storage unit 203 and the connection point of the bypass switch. Connect (2300). Then, the new input voltage value is detected and stored in the input voltage value storage unit 207 again (2400), and the output of the new voltage value is alternately controlled (2500). At this time, when a new voltage value is replaced, the output unit is controlled to soften up or down the voltage value in order to smoothly raise (or lower) the voltage because a voltage difference is generated from the previously stored voltage value.

Here, it may be more preferable to configure the system so that a user can arbitrarily set the time difference from instantaneous power failure to recovery time, which is the target of step 2100 of FIG. 6. This is because the user can actively respond to the need to set the desired recovery time according to the electrical performance of the electrical device using the power failure compensation device according to the present invention. For example, depending on the electrical equipment, there may be a device that is greatly affected even in the case of a power failure of about 1 second, or there may be a device that does not have a big problem even in a power failure of a few seconds. By allowing the user to set the recovery time, the power failure compensation device according to the present invention can more actively cope with power failure such as instantaneous power failure, thereby maximizing the utility of the present invention. The recovery time setting unit (not shown) may be installed in the control unit 124 shown in FIG. 3, but is not necessarily limited thereto. For example, the control unit 124 may be provided separately as one component of the apparatus of the present invention.

Additional Examples

The basic configuration of the present invention and the embodiments for implementing the same have been described above. In the power failure compensation device according to the present invention, the following deformable embodiments may be added.

Means for monitoring capacitor charge can be installed. In the power failure compensation device according to the present invention, when the power failure occurs, the bypass switch is shut off and the compensation voltage is generated by using the power charged in the capacitor. Will be able to operate the device. For example, monitoring a capacitor's charge can be recorded or notified when the charge remains below about 20% and controlled to shut down the system.

The configuration and operation of the power failure compensation device according to the present invention have been described with reference to specific embodiments and several modified embodiments. However, the technical scope of the present invention is not limited to the embodiments, but the technical matters interpreted by the claims and their equivalents are obvious.

According to the present invention, the switching time of the bypass switch can be minimized in the case of instantaneous low voltage and instantaneous power failure, thereby minimizing the occurrence factor of the surge voltage. In addition, unlike the related art, both the upper and lower ranges of the input voltage can be sensed, and since the power is recovered in synchronization with the stored zero point even during the recovery after the instantaneous power failure, no surge voltage is generated and the reactive power can be suppressed. In addition, since the user can set the recovery time after instantaneous power failure, more efficient power compensation is possible in the use of the electric device, and it is possible to reduce the failure of the electric device and extend the life. In addition, it is possible to perform a more efficient management in the operation of the electrical equipment by storing and monitoring the change in the input power source.

Claims (8)

Power input through the power input terminal is output to the power output terminal along the output line through the bypass switch along the input line, A phase detection unit connected to an input branch line branched from the input line to detect a phase of an input voltage and store a zero point; A voltage detector connected to an input branch line branched from the input line to detect an input voltage and store a current input voltage; A voltage compensating means for generating a compensation voltage and outputting it through the power output terminal when it is determined that the voltage abnormality is generated in the voltage detection unit; And a controller for blocking the bypass switch and controlling the voltage compensation means to output a compensation voltage when a voltage abnormality occurs according to the signals received from the phase detector and the voltage detector. The control unit, A position value storage unit for storing the zero point by processing the phase value of the input voltage, an input voltage monitoring unit for monitoring whether the input voltage falls within the upper and lower limits, and an input voltage value storing the input voltage value currently input And a bypass switch operation unit to block or connect the bypass switch. When the input voltage exceeds the set upper limit and lower limit ranges, the voltage compensating means is controlled to output the rated voltage as a compensation voltage after the bypass switch is cut off. In the instantaneous power failure, the voltage compensation means is controlled to cut off the bypass switch and output a compensating voltage equal to the voltage value stored in the input voltage value storage unit. And connecting the bypass switch when the power is restored after the instantaneous power failure, and delaying the connection time of the bypass switch to be synchronized with the zero point stored in the phase value storing unit. According to claim 1, wherein the voltage compensation means, Capacitor charging unit for converting AC current through the input branch line to DC, A capacitor charged with the DC voltage converted by the capacitor charger, A DC / AC inverter for discharging the DC electricity charged in the capacitor and converting it to AC, and adjusting the voltage of the DC electricity discharged from the capacitor under control of a controller; AC power converted from the DC / AC inverter is input power supply compensation device comprising a transformer for outputting the compensation voltage to the power output terminal on the output side. delete The method of claim 1 or 2, wherein the control unit When the power recovery is performed after instantaneous power failure, the compensation voltage is replaced with a new input voltage value instead of the value stored in the input voltage value storage unit, and is softly replaced by a new voltage by soft up or down. Compensator. The method according to claim 1 or 2, Power failure compensation device further comprises a recovery time setting unit that allows the user to arbitrarily set the standby time difference from instantaneous power failure to recovery time. The method according to claim 1 or 2, And a memory for storing the variation of the input voltage and a means for outputting the stored value. The method according to claim 1 or 2, And a means for storing and monitoring the change value and the change point of the input voltage and history data relating to compensation control of the controller. The method of claim 2, And a means for monitoring the amount of charge charged in the capacitor.

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