RU34283U1 - Uninterruptible power supply unit - Google Patents

Description

Uninterruptible power supply unit

The utility model relates to the field of electrical engineering and can be used as an uninterruptible power supply unit (UPS) in low-voltage complete devices and power supply systems, where high demands are made both on the quality of electricity and the level of mass and size characteristics.

A UPS is known that contains a network to which a rectifier, an inverter, connected in series to a rectifier and a battery connected between

rectifier and inverter 1. This UPS has been widely used in various power supply systems, since it provides power supply to both direct current consumers and AC consumers, however, this UPS does not provide for the shutdown of power converters in emergency situations.

The closest, in terms of technical support1, to the proposed one is the UPS, you can use it in uninterruptible power systems, and it contains a rectifier connected to a three-phase network, an inverter connected in series with an electronic key and a battery connected between the rectifier and the inverter 2. The three-phase rectifier used in the UPS is equipped with a voltage regulator or stabilizer, so a stabilized constant voltage with a low level of bullets is formed at its output, as well as at the input of the inverter ations. The classic three-phase rectifier circuit contains

IPC N 02 J3 / 00

a three-phase converter transformer, the rectification circuit which can be used as a three-phase two-half-wave thyristor rectification circuit and forming a cascade, which uses a smoothing filter 3, while the filter choke can be represented by a set of series-connected chokes, the total coil inductance of which is equal to the inductance of one common choke , and the filter capacitor can be represented as a chain of parallel-connected capacitors, the total whose bone is equal to the capacitance of the common capacitor. In turn, the inverter used in the UPS is a combination of an inversion circuit, an output three-phase transformer and a three-phase resonant filter connected in series with it, containing in each phase a series-connected inductor and a parallel-connected capacitor 4,5. The listed UPS elements are distinguished by the reversibility property: the converter transformer is reversible with a three-phase output transformer, the rectification circuit is reversible with an invert circuit and the smoothing filter is reversible with a resonance filter 1 ... 5. Thus, the main disadvantages of the existing UPS are the presence in the circuit of devices that perform the same functions, relatively low efficiency, large mass and dimensions, as well as cost.

The technical result of the utility model is to increase the efficiency and reduce the cost of the UPS due to the exclusion from its circuit of elements that perform the same functions.

This technical result is achieved in that in an uninterruptible power supply unit containing a three-phase alternating current source, a direct current source, a transformer.

the inverter, the current distribution device and the forming cascade are introduced, and the inverter is reversible, while the outputs of the direct current source and the alternating current source are connected to the corresponding first and second inputs of the current distribution device, the three-phase voltage output of which is connected to the high-voltage input / output of the transformer and through the resonant filter forming a cascade with three-phase current buses, a low-voltage input / output of a transformer connected to an input / output of an alternating current reversible invert an ora, the DC input / output of which through the smoothing filter of the forming cascade is connected to the DC buses, the DC voltage output of the current distribution device is connected to the DC input / output of the reversible inverter, the first control output of the current distribution device is connected to the control input of the reversible inverter. In addition, the forming cascade is configured to switch the resonant filter circuit to the smoothing filter circuit by a signal from the second control output of the current distribution device connected to the control input of the forming cascade.

In FIG. 1 shows a block diagram of the UPS. Figure 2 shows a diagram of a converter transformer and a reversible inverter. On Fig.3 presents a diagram of a smoothing filter having three series-connected cascades. Figure 4 shows a diagram of a three-phase resonant filter.

The device contains 1 a three-phase AC source 1, a DC source 2, a current distribution device 3, a transformer 4, a reversible inverter 5 forming a cascade 6, a three-phase current bus 7 and a DC bus 8, while the transformer 4 is equipped with a high voltage input / output 4-1 and

low-voltage input / output 4-3, the reversible inverter 5 is endowed with an input / output of direct current 5-1, and an input / output of alternating current 5-2 and a control input 5-3, the forming cascade 6 is equipped with an input of direct rectified voltage 6-1, an output DC 6-2, AC input 6-3, AC three-phase current output 6-4 and control input 6-5, and current distribution device 3 is endowed with AC 3-1 input, DC 3-2 input, AC 3 output -3, DC output 3-4, the first control output is reversible 3rd inverter 3-5 and the second control output forming cascade 3-6. A transformer circuit 4 containing two three-phase windings and a core is shown in FIG. 2. The reversible inverter 5 is shown in FIG. 2 (the thyristor control circuit is not shown in the drawing). The forming cascade 6 consists of chokes and capacitors interconnected according to the resonant filter circuit (Fig. 4) with the ability to switch elements and connections according to the smoothing filter circuit (Fig. C) when the signal at its control input 6-5 changes. The transition of the reversible inverter 5 and the forming stage 6 from the rectification mode to the inversion mode is carried out according to the signals of the current distribution device 3, which provides control of the presence of voltage, control of the voltage value, control of the current type, protection against overloads and short circuits, as well as the issuance of control signals depending on the kind input voltage current. The current rectification channel (Fig. 1) is formed by a transformer 4 (input 4-1 and output 4-2), a reversible inverter 5 (input 5-2 and output 5-1) operating in the rectification mode by a forming cascade 6 (input 6-1 and output 6-2) and DC busbars 8. The current inversion channel is formed (Fig. 1) by a reversible inverter 5 (input 5-1 and output

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5-2), transformer 4 (input 4-2 and output 4-1), the forming cascade 6 (input 6-3 and output 6-4) and three-phase current buses 7. These UPS elements such as transformer 4, reversible inverter 5 and current distribution device 3 are serially produced by domestic manufacturers of converting equipment: Moscow Searchlight Plant, ChEAZ OJSC and others. In general, two signals are implemented in current distribution device 3, during the generation of which the functioning elements of the UPS in a certain order are shown in the table. The order of inclusion of the UPS elements.

It follows from the table that the appearance of signal 1 leads to the creation of a current rectification channel, and the appearance of signal O leads to the creation of a current inversion channel. It can be noted that UPS is usually used in power supply systems for critical consumers, where the usual mode (power from the industrial network) is connected and alternates with the emergency mode, in which the main source of electrical energy is the battery.

The uninterruptible power supply unit operates as follows. In a static state, when the three-phase AC source 1 and the DC source 2 are disconnected, the current distribution device 3 does not work, the transformer 4, the reversible inverter 5 and the forming cascade 6 are de-energized on the DC buses 8 and on the three-phase current buses 7 (phases L1, L2 and L3) voltage

Table

is absent. If there is voltage from the source of three-phase alternating current 1, the current-distributing device 3 transfers it to the current rectification channel and it enters the high-voltage input 4-1 of transformer 4, where it drops to a predetermined value and is removed from the low-voltage output 4-2, coming to the AC input 5 2 of the reversible inverter 5. In addition, the current distribution device 3 generates a signal from the control output of the reversible inverter 3-5 and this signal arriving at the control input 5-3 of the reversible inverter 5 puts the latter into the output mode pitting, after which the direct rectified voltage from the DC output 5-1 of the reversible inverter 5 is fed to the input of the direct rectified voltage 6-1 of the forming cascade 6. The current distribution device 3 also generates a control signal of the forming cascade, which from the output 3-6 enters the control input 6-5 of the forming cascade 6. According to this signal, the forming cascade 6 switches the elements to the circuit of FIGS. 3-4 performs the function of a smoothing filter and a constant voltage is applied to the DC bus from the DC output 6-2 constant current 8. If there is voltage from a direct current source 2, the current-distributing device 3 transfers it to the current inversion channel and it goes to the DC input 5-1 of the reversible inverter 5, where it is inverted and from the AC output 5-2 of the specified inverter 5 goes to low-voltage input 4-2 of transformer 4 where it increases in amplitude and is transferred from the high-voltage output 4-1 to the input of alternating current 6-3 of the forming cascade 6. The reversible inverter 5 and the forming cascade 6 are controlled from the current distribution device 3 for the same relationships as before. Forming cascade 6 passing into the mode of formation of a sinusoidal curve produces a sinusoidal 6

three-phase voltage from the output of the alternating three-phase current 6-4 to the buses of the three-phase current 7. Thus, the introduction of current distribution device 3 can reduce the number of UPS elements, reduce weight and cost, increase the efficiency of the unit and the power supply system as a whole.

Sources Iriyutyh into account

1 Netsvet V.A. Power supply for communication devices. M., Communication, 1976,

p. 41, fig. 30 (analogue).

2 Power supply for communication devices. Under. ed. V.E.Kitaev. M., Radio

and Communication, 1988, p. 232, Fig. 9-11 (prototype).

3 Romash E.M. Secondary Power Supplies

electronic equipment. M., Radio and Communications, 1981, p. 88, fig. 5-46

(rectifier circuit).

4 Gubanov V.V. Semiconductor converters with output stabilizers. L., Energy, 1972, p. 120, Fig. 5-13 (inverter circuit).

5 Power Supply for Communication Devices, ed. O.A.Domoratsky, M., Radio Communication, 1981, p. 246, Fig. 8.9 (UPS circuit).

Authors:, / bh - Kirillov P.P.

l G Labanov A.V.

Claims (2)

1. An uninterruptible power supply unit containing a three-phase alternating current source, a direct current source, a transformer, an inverter, characterized in that a current distribution device and forming cascade are introduced, and the inverter is reversible, while the outputs of the direct current source and the alternating current source are connected to the corresponding first and the second inputs of the current distribution device, the three-phase voltage output of which is connected to the high-voltage input / output of the transformer and through the resonant filter of the cascade with three-phase current buses, the low-voltage input / output of the transformer is connected to the AC input / output of a reversible inverter, the DC input / output of which is connected to the DC bus through the smoothing filter of the forming cascade, the DC voltage output of the current-distributing device is connected to the DC input / output reversible inverter, the first control output of the current distribution device is connected to the control input of the reversible inverter. 2. The unit according to claim 1, characterized in that the forming cascade is configured to switch the resonant filter circuit to a smoothing filter circuit by a signal from the second control output of the current distribution device connected to the control input of the forming cascade.