Power supply equipment backup system for interruption of service
First Claim
1. A power supply equipment backup system for interruption of service for supplying power from a commercial AC power source to a device load through a main power supply line (1) and from a battery DC source (B) to the device load through an auxiliary power supply line (2) connected in parallel with the main power supply line in relation to ground, which comprises:
- (a) an AC switch (1a) connected to the commercial AC power source;
(b) a commercial AC power source mointoring means (20) connected to the commercial AC power source for outputting a power-on signal A to said AC switch (1a) for activating said AC switch (1a) to supply the commercial AC power source to the device load through the main power supply line when the commercial AC power source changes to a normal condition;
(c) power inverter means (10) having an inductor (Li) and connected between the battery DC power source (B) and the device load for supplying an inverter power source to the device load through the auxiliary power supply line whenever the commercial AC power source is abnormal or normal;
(d) basic inverter frequency presetting means (30) for outputting a triangular wave signal to determine an inverter frequency substantially equal to said commercial AC power source frequency on the basis of a preset inverter frequency value (fo);
(e) basic inverter voltage presetting means (40) connected to an output terminal of said inverter means (10) for outputting a DC voltage signal to determine an inverter voltage substantially equal to said commercial AC power source voltage on the basis of a preset inverter voltage value (Vo);
(f) inverter controlling means (50) connected to said inverter frequency presetting means (30) and said inverter voltage presetting means (40) for comparing the triangular wave signal with the DC voltage signal in voltage level and for outputting inverter control signals to said inverter means (10), inverter frequency being determined by the triangular wave signal frequency, and further inverter voltage being determined by time intervals during which the triangular wave signal exceeds the DC voltage signal in voltage level,(g) a main power supply line inductor (Ll) connected between said AC switch (1a) and the device load with an output terminal of said inverter means (10) connected to a junction point between said inductor (Ll) and the device load;
(h) phase matching means (60) including phase difference detecting means connected between the commercial AC power source and said basic inverter frequency presetting means (30) and connected by a feedback loop from said inverter controlling means (50), said phase matching means detecting a phase difference between the commercial AC power source and the inverter power source, outputting a phase difference signal to said basic inverter frequency presetting means (30) to adjust the inverter power source frquency (fi) to the commercial AC power source frequency (fc), and outputting a phase match signal B to said commercial AC power source monitoring means (20) for allowing said monitoring means (20) to output a power-supply signal C to said AC switch (1a) to supply the commercial AC power source to the device load when the inverter power source has matched the commercial AC power source in phase, said phase matching means (60) being connected to said basic inverter frequency presetting means (30) in response to the power-on signal A and disconnected from said basic inverter frequency presetting means (30) in response to the phase match signal B; and
(i) a battery charging power presetting means (70) connected between the output terminal of said inverter means (10) and said basic inverter frequency presetting means (30), said battery charging power presetting means (70) reducing inverter frequency (fi) to supply a battery charging power from the main power supply line (1) to the auxiliary power supply line (2) by passing a charging current from the commercial AC power source to the battery through said inverter means (10) in dependence upon a small phase difference between the commercial AC power source and the inverter power source caused by a small frequency difference between the two, said battery charging power presetting means (70) being connected to said basic inverter frequency presetting means (30) in response to the power-supply signal C outputted from said commercial AC power source monitoring means (20) when the commercial AC power source changes to the normal condition.
1 Assignment
0 Petitions
Accused Products
Abstract
A commercial AC source is connected to a load through the main line (1) via an AC switch (1a) only when the AC source is normal, and an inverter power source (10) is connected to the load through the auxiliary line (2) whether the AC source is normal or abnormal. In the case when the AC source changes from abnormal to normal, since the AC source is connected to the main line (1) after the inverter phase has matched the AC source phase, substantially no effective power is transmitted from the main line to the auxiliary line or vice versa, while a required power is being supplied from the AC source to the load (not from the inverter). Further, since an inverter inductor (Li) and a main line inductor (Ll) are connected in the main and auxiliary lines, respectively, even if the AC source voltage fluctuates, it is possible to regulate the load voltage at a constant level by virtue of an inverter current flowing from the AC source to the inverter source or vice versa. Furthermore, it is also possible to charge an inverter battery by reducing inverter frequency a little lower than that of the AC source.
43 Citations
15 Claims
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1. A power supply equipment backup system for interruption of service for supplying power from a commercial AC power source to a device load through a main power supply line (1) and from a battery DC source (B) to the device load through an auxiliary power supply line (2) connected in parallel with the main power supply line in relation to ground, which comprises:
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(a) an AC switch (1a) connected to the commercial AC power source; (b) a commercial AC power source mointoring means (20) connected to the commercial AC power source for outputting a power-on signal A to said AC switch (1a) for activating said AC switch (1a) to supply the commercial AC power source to the device load through the main power supply line when the commercial AC power source changes to a normal condition; (c) power inverter means (10) having an inductor (Li) and connected between the battery DC power source (B) and the device load for supplying an inverter power source to the device load through the auxiliary power supply line whenever the commercial AC power source is abnormal or normal; (d) basic inverter frequency presetting means (30) for outputting a triangular wave signal to determine an inverter frequency substantially equal to said commercial AC power source frequency on the basis of a preset inverter frequency value (fo); (e) basic inverter voltage presetting means (40) connected to an output terminal of said inverter means (10) for outputting a DC voltage signal to determine an inverter voltage substantially equal to said commercial AC power source voltage on the basis of a preset inverter voltage value (Vo); (f) inverter controlling means (50) connected to said inverter frequency presetting means (30) and said inverter voltage presetting means (40) for comparing the triangular wave signal with the DC voltage signal in voltage level and for outputting inverter control signals to said inverter means (10), inverter frequency being determined by the triangular wave signal frequency, and further inverter voltage being determined by time intervals during which the triangular wave signal exceeds the DC voltage signal in voltage level, (g) a main power supply line inductor (Ll) connected between said AC switch (1a) and the device load with an output terminal of said inverter means (10) connected to a junction point between said inductor (Ll) and the device load; (h) phase matching means (60) including phase difference detecting means connected between the commercial AC power source and said basic inverter frequency presetting means (30) and connected by a feedback loop from said inverter controlling means (50), said phase matching means detecting a phase difference between the commercial AC power source and the inverter power source, outputting a phase difference signal to said basic inverter frequency presetting means (30) to adjust the inverter power source frquency (fi) to the commercial AC power source frequency (fc), and outputting a phase match signal B to said commercial AC power source monitoring means (20) for allowing said monitoring means (20) to output a power-supply signal C to said AC switch (1a) to supply the commercial AC power source to the device load when the inverter power source has matched the commercial AC power source in phase, said phase matching means (60) being connected to said basic inverter frequency presetting means (30) in response to the power-on signal A and disconnected from said basic inverter frequency presetting means (30) in response to the phase match signal B; and (i) a battery charging power presetting means (70) connected between the output terminal of said inverter means (10) and said basic inverter frequency presetting means (30), said battery charging power presetting means (70) reducing inverter frequency (fi) to supply a battery charging power from the main power supply line (1) to the auxiliary power supply line (2) by passing a charging current from the commercial AC power source to the battery through said inverter means (10) in dependence upon a small phase difference between the commercial AC power source and the inverter power source caused by a small frequency difference between the two, said battery charging power presetting means (70) being connected to said basic inverter frequency presetting means (30) in response to the power-supply signal C outputted from said commercial AC power source monitoring means (20) when the commercial AC power source changes to the normal condition. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of supplying power from a commercial AC power source to a device load through a main power supply line (1) and from a power inverter (10) including a battery DC power source (B) to the device load through an auxiliary power supply line (2) connected in parallel with the main power supply line in relation to ground, which comprises the following steps of:
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(a) presetting a basic inverter frequency (fo) substantially near a frequency of the commercial AC power source; (b) presetting a basic inverter voltage (Vo) substantially near a voltage of the commercial AC power source; (c) activating the power inverter connected in the auxiliary power supply line (2) at the present basic frequency and voltage to supply the battery DC power source to the device load through the power inverter; (d) detecting whether the commercial AC power source is normal or abnormal; (e) when the commercial AC power source changes from abnormal to normal, detecting a phase difference between the commercial AC power source and inverter power source; (f) matching the inverter power source phase with the commercial AC power source phase in dependence upon the detected phase difference; (g) connecting the commercial AC power source to the device load when the inverter power source matches the commercial AC power source in phase to prevent power from being substantially transmitted between the main power supply line and the auxiliary power supply line, to supply an effective power required for the load from the commercial AC power source to the load and to regulate the device load voltage at a constant level; (h) if the commercial AC power supply source is abnormal, disconnecting the commercial AC power source from the device load in the main power supply line (1); (i) if the commercial AC power supply source is normal, connecting the commercial AC power source to the device load in the main power supply line (1) to supply the commercial AC power source in addition to the battery DC power source supplied through the power inverter in the auxiliary power supply line (2); (j) presetting a desired battery charging power Ps in a form of voltage; (k) reducing power inverter frequency fo to lower than that of the commercial AC power source in dependence upon the preset battery charging power Ps ; and (l) activating the power inverter at a reduced frequency to supply power from the main power supply line (1) to the auxiliary power supply line (2) for charging the battery DC power source through the power inverter. - View Dependent Claims (11, 12, 13, 14, 15)
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Specification