KR830000297B1 - Three phase power controller - Google Patents

Abstract

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Description

Three phase power controller

1 is a block diagram illustrating a power control device in accordance with the present invention for receiving a three phase input line voltage and supplying a controlled output of three phases.

2 is a schematic circuit diagram showing an embodiment of a power control device according to the present invention.

3 is a functional schematic diagram of a control part of the power control device of FIG.

The present invention relates generally to devices for controlling the power consumption of voltage adjustable loads such as light loads in office buildings, industrial plants and schools or other such buildings. In particular, the present invention relates to a voltage control device for a three-phase power source that can adjust power consumption.

Energy conservation is an important concern today. One effective way to conserve energy is to eliminate unnecessary power usage by adjusting power consumption. For example, conventionally known devices for adjusting light load have a transformer connected to a bucking or boosting circuit. Such transformers usually form a static state without any dynamic control. Since there is no dynamic control, if the voltage drops too low or rises too high, the fluorescent lamp will not light or the fluorescent lamp will not operate normally.

For these reasons, such transformers have generally not been used to control fluorescent lamp circuits.

Conventional transformer devices with a control such as a variac generally lacked suitable sensing circuitry that can be prepared to favorably control power consumption or light load.

Semiconductor devices have also been used in light load regulators. Such semiconductor devices generally have various undesirable characteristics as phased devices. For example, these devices tend to cause significant radio frequency interference (RFI). Moreover, they are generally not available for fluorescent lights without special arrangements for fluorescent ballasts or auxiliary controls. Also, triac, diac or other semiconductor devices generally do not have protection against voltage surges. Since there is no protection means, the control element of the semiconductor is frequently damaged when the lamp is turned off.

US Patent Application Nos. 839 and 748, filed on October 5, 1977 by the applicant, disclose a single-phase power control device that is particularly useful for light loads such as incandescent and fluorescent lamps. The power control device is located between the power source and the load, usually between the circuit breaker and the lamp in a single phase circuit. The power control device reduces the voltage transmitted to the load, thereby reducing the power consumed by the load. Power can be reduced by more than 10% without damaging the brightness of the light. Even if the light output decreases considerably, it can save more than 40%. The device includes a device that controls operation according to voltage, delay, clock time and external conditions. The device has a device that can apply an input voltage immediately when the output voltage falls below a predetermined threshold, thereby automatically reducing the output voltage.

The device also includes a delay for the timing cycles when the output voltage to the load is maintained at or at a reduced level. For example, the output remains at a reduced level for most of the time except that the output voltage returns to a high level periodically for a short period of time. Each time the output returns to a high level, the fluorescent load on the line can light up.

An object of the present invention is an improved power control device.

Another object of the invention is a voltage control device for three-phase voltage.

Another object of the invention is a three phase voltage control device which can be operated directly on an incoming three phase voltage line.

Another object of the invention is a three-phase voltage control device capable of controlling a plurality of load circuits such as fluorescent lamps.

Another object of the invention is a three phase power control device which can be operated automatically and can also be operated manually.

In summary, according to the present invention, the voltage control device includes first, second and third transformer devices, each of which has one input terminal and a plurality of output terminals. A device is provided for connecting one input voltage phase to one input terminal of each transformer device, and a contact device associated with each transformer device selectively contacts the output terminal of each transformer device. A manual switch device is installed to manually select a contact device to obtain a desired output voltage, and an automatic switch device is installed to automatically select a contact device to obtain a desired voltage. Bypass switches can be installed to connect the input voltage lines directly to the output voltage lines without a voltage drop.

According to one feature of the invention there is provided a timing device for automatically switching between high and low output voltages and a recycling device for instantaneous reapplication of high voltages.

According to still another feature of the present invention, there is provided a single-phase control device for removing voltage from one or more phases or controlling power in these phases.

The objects and features of the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing the power controller 10 of the present invention connected to receive the three-phase input voltage indicated by 12 and to send a controlled three-phase output voltage to the sub-board 14. For example, power control The device is preferably connected to the input line side of the three-phase optical substrate. The bypass circuit 16 is provided for directly applying the three-phase voltage to the three-phase output line. The distribution plate 14 usually has several single phase load circuits 18 including fluorescent lamps.

The control device 10 has a manual actuating mode and an automatic actuating mode and an OFF, ie blocking mode. In the blocking mode the bypass circuit 16 will be used. The control device can be operated to supply a predetermined high or low voltage to the recycling device, for example, to instantaneously recycle a high voltage to periodically turn on the fluorescent lamp.

2 is a schematic diagram showing one embodiment of a power control device according to the present invention. The input lines denoted by (L ₁ ), (L ₂ ), (L ₃ ) are connected to the inputs of the autotransformers 22, 24, 26 through the three-phase circuit breakers 20, respectively. The neutral line (N) is also connected to one input of the single winding transformers 22, 24 and 26.

Each output of a single winding transformer has a large number of taps or contacts that are engaged by a pair of switches, such as (22-1) and (22-2) in the single winding transformer 22. Similarly, switches 24-1 and 24-2 are provided for single winding transformers 24, and switches 26-1 and 26-2 are provided for single winding transformers 26. For each transformer a group of switches 22-1, 24-1, 26-1 is connected to a tripole circuit breaker 30 via a first tripole magnetic contactor 28, the It is connected to the three-pole circuit breaker 30 through the remaining contacts 22-1, 24-2, 26-2, 28, and the remaining contacts 22-2, 24-2, 26-2 of each transformer. ) Is connected to the tripolar circuit breaker 30 through the second tripolar magnetic contactor 32. When the line input voltage is 480V, the voltage output between the line voltage and the line neutral line is as follows depending on which tap the switches 22, 24 and 26 are placed on.

The other group of the three-pole circuit breakers 30 is connected to the three-phase output line through the power meter 31. Therefore, a higher voltage is applied to the output line when the magnetic contactor 28 is closed than when the magnetic contactor 32 is closed. As will be described with reference to FIG. 3, the contacts 28 and 32 are alternately closed and not closed at the same time.

In the load shedding (e.g., phase control) circuit, single-pole switches 33, 34, 36 are provided at each output line of the circuit breaker 30. Relay times and control circuits 38 are provided so that one or more phases of the output can be differential for load seeding. Alternatively, a single phase voltage control device as disclosed in US Pat. No. 839,748, described above, may be connected to each line exiting breaker 30.

The bypass three-pole circuit breaker 40 connects the three-phase input line to the three-phase output line whenever the control device is cut off.

The low voltage device 42 is connected to each three phase input line to detect a low voltage state on the input line. When under voltage, the device automatically recycles to the line voltage output and remains in that state until the input line is below the operating voltage level.

The primary winding of the transformer 44 is connected across both input lines, and the secondary winding is connected to supply the dropped voltage to the control circuit. Usually the line input voltage is about 480V and the control circuit operates from 120V.

Thus, transformer 44 lowers the voltage to the desired operating level for the control circuit.

Referring now to FIG. 3, a control device for the switches and circuits of FIG. 2 is illustrated. It can be seen that the circuit shown is connected between the 120V outputs of the transformer 44 of FIG. The switch 50 is used to determine the high voltage output and the low voltage output from the voltage controller in the passive mode. The three-pole three-stage switch 52 determines "manual", "off", and "automatic" operation by the contacts 52-1, 52-2, and 52-3.

The high output terminal of the switch 50 is connected to the circuit ground via the manual position of the switch 52-1 and the contact 54 and the relay 56. The low voltage side switch 52-1 of the manual switch 50 is connected to the circuit ground via the contact point 60 and the relay 62. When current flows through the relay 56, the contact 60 opens and the magnetic contact 28 of FIG. 2 closes. Similarly, when current flows through the relay 62, the contact 54 opens and the magnetic contact 32 of FIG. 2 closes. Thus, in the passive mode, the switch 50 controls the magnetic contacts 28 and 32 and determines whether a high voltage or a low voltage is applied as an output.

When the switch 52 is placed to operate the auto mode, a high voltage output is provided as the current flows through the contacts 64, the switches 52-1, the contacts 54, and the relays 56. In the case of the red voltage output in the automatic mode, current flows through the contact 66, the switch 52-1, the contact 60, and the relay 62. Contacts 64 and 66 are controlled by the same relay (to be described below). Thus, switch 64 is closed when the relay loses energy, and switch 66 is closed when the relay is charged with energy.

The switch 52-3 is connected to the 120V line only in the auto mode, and includes a timer contact 68, a low voltage contact 70, a first time delay contact 72, a second time delay contact 74, and a high- It is connected in series with the low selector relay 76. The time delay relay 78 is connected between the contacts 72 and 74 to the circuit ground. The timer 80 controls the contact 68 and is connected across the control line voltage.

When the switch 52-3 is in the open or manual position at the time of operation, no voltage is applied to the timer circuit so that it can operate. When switch 52-3 is in automatic mode, a voltage is applied to contact 68 through the switch. When the timer 80 is in the high voltage portion around the timing cycle, the switch 68 opens and the circuit becomes inoperable. Under these conditions, the switch 64 is closed and the high voltage magnetic contact 28 is closed by energizing the relay 56.

When the timer 80 is in the low voltage cycle during the timing cycle, the switch 68 is closed and current passes through the contact 70 (assuming the line is not undervoltage) (and the close contact 72 and the time delay relay 78). The time delay relay 78 may be adjusted to provide a delay in switching from high voltage to low voltage After a set delay period, the relay 78 closes the contact 74 and accordingly to the relay 76. Energy is supplied by energizing the relay 76, which opens the high voltage contact 64 and closes the low voltage contact 66, thereby applying current through the switch 52-1, the contact 60, and the relay 62. The current through the contact 64 is cut off when energy is supplied to the relay 76, and the contact 54 is opened when energy is supplied to the relay 62. Thus, the high voltage line contactor 28 is a voltage control device. Is removed from and the low voltage line contactor 3 2 is applied.

In automatic mode operation, a high voltage can be instantaneously reapplied to the output line by a recycle timer 82 which is operated by closing the unipolar momentary contact switch 84.

Closing switch 84, timer 82 opens contact 72 for a set period of time, interrupting current through relay 76, consequently closing switch 64 and closing switch 66. Open. By closing the switch 64, a high voltage is applied to the output line. After the timer 82 has lost energy (depending on its time cycle) the contact 72 is closed again and energy is supplied to the low voltage relay 76 after a delay period determined by the timer 78.

The line voltage indicator 90 is connected in series with the contact 92 at both ends of the control voltage line, and is supplied with energy by closing the contact 96 as energy is supplied to the relay 56.

From the above description of the embodiment, it has been shown that the three-phase control device according to the present invention is equipped with a bypass device that permits manual or automatic mode operation and applies line voltage directly to the output line.

In the operation of the passive mode, a high output voltage or a low output voltage is obtained by manual operation of the clutch. In automatic mode operation, the dropped voltage is automatically obtained by a timer device which makes an appropriate time delay upon switching from high voltage to low voltage. In addition, a recycling device is installed to instantaneously reapply high voltages during auto mode operation. Furthermore, by placing switches on each of the three phase output lines, load seeding (phase control) can be used, thereby allowing one or more phases of the output to lose energy. The control circuit can be bypassed by a suitable circuit breaker.

Although the present invention has been described with reference to particular embodiments, the description is illustrative of the invention and is not limited thereto.

Various modifications and applications will be possible to those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (1)

Each of the first, second, and third transformers has one input terminal and a plurality of output terminals, and a device for connecting an input voltage line with an input terminal of the transformer, and a contact device selectively connected to the output terminals of the transformers. There is a manual switch for manually selecting the contact devices to obtain the desired output voltage, there is an automatic switch for automatically selecting the contact devices to obtain the desired output electrolyte according to the required energy, The automatic switch includes a sensing device, a device for connecting the contact devices to the output voltage line, and a three-phase power control device is provided with a bypass switch for connecting the input voltage line directly to the output voltage line.

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