JP2002233079A - Uninterruptive switching regulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an uninterruptive switching regulator capable of stably driving load even in any condition while contriving the reduction of consumption power. SOLUTION: During power failure, before the power supply of an alternating current side power supply circuit A stops, a direct current side power supply circuit C is driven, and in the restoration of power a control means 19 for driving the direct current side power supply circuit C is provided until power supply from the alternating current side power supply circuit A is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive system for driving a load with an output obtained by rectifying an AC voltage from a commercial AC power supply (AC) by an AC-side power supply circuit. Uninterruptible switching regulator for driving a load with the output from the DC side power supply circuit provided with precision control, especially for crime prevention, disaster prevention, communication, information (server computer, FA personal computer, etc.), medical precision machinery and automatic machinery The present invention relates to an uninterruptible switching regulator used for operating devices of equal importance. Here, a power outage refers to an interruption of power (current) supply, for example, when an electric power supply from an electric power company is interrupted,
It refers to the case where the supply power is cut off due to the breaker being dropped, the outlet being disconnected, or the disconnection.

[0002]

2. Description of the Related Art In particular, server computers and the like are required to operate continuously for 24 hours and 5 years without stop. Therefore, normally, an AC voltage from a commercial AC power supply is supplied to a secondary DC output circuit through an AC power supply circuit connected to a primary winding of a high-frequency transformer, and an abnormal voltage such as a power outage By supplying power to a secondary DC output circuit via a DC power supply circuit connected to a tertiary winding of a transformer, the load can be operated continuously. When the power failure is restored, power is supplied to the secondary DC output circuit via the AC power supply circuit. In order to drive the load stably during the power failure, the power supply from the DC side power supply circuit must be performed in a state without a time difference, that is, instantaneously, so that the switching element of the DC side power supply circuit is used. It was configured to always maintain the active state.

According to the above configuration, even when power is normally supplied from the AC side power supply circuit,
Since the switching element of the DC-side power supply circuit is in an active state, the DC-side power supply circuit is in an idling operation state, and although the power required for the idling operation is very small, it is large in long-term use. Power consumption had become.
When a power failure occurs, the evacuation time to the backup memory or the like in the information device can be maintained.
The AC power supply circuit has a capacitor. for that reason,
If the power outage time is long, even if the power outage is restored, the power supply (voltage) from the AC side power supply circuit becomes unstable unless the completely discharged capacitor is charged to some extent. In some cases, the load could not be driven sufficiently.

[0004]

SUMMARY OF THE INVENTION In view of the above situation, the present invention seeks to solve the problem by reducing the power consumption and stably driving the load in any situation. It is an object of the present invention to provide an uninterruptible switching regulator.

[0005]

In order to solve the above-mentioned problems, an uninterruptible switching regulator according to the present invention has a rectifier circuit for rectifying an AC voltage from a commercial AC power supply and an input voltage from the commercial AC power supply. An input voltage detection circuit for detecting that the voltage is lower than a voltage, a first switching element that is switched between an active state and a stopped state based on a detection signal from the input voltage detection circuit, and the input voltage detection circuit. When the input voltage is lower than the set voltage, one or more AC-side power supply circuits including a capacitor or the like for supplying power for a predetermined time are connected to the primary winding of the high-frequency transformer, and the secondary of the high-frequency transformer is connected. Connect a rectifying and smoothing circuit to the side winding and connect a secondary DC output circuit to supply DC output power to the load, A single or a plurality of backup power supply circuits including a second switching element or the like that can be switched between an active state and a stopped state based on a detection signal from an input voltage detection circuit are connected, and the input voltage from the commercial AC power supply is If the input voltage detection circuit detects that the voltage is lower than the set voltage, the AC power supply circuit is activated by activating the second switching element while power is supplied by the capacitor. And driving one or more backup power supply circuits overlapping for a predetermined time, and when the input voltage detection circuit detects that the input voltage from the commercial AC power supply is equal to or higher than a set voltage, After the first switching element is activated and the power supply is started by the AC power supply circuit, the second switching element is stopped after a predetermined time has elapsed. It is characterized in that the power supply circuit for the AC power supply circuit and a single or a plurality of backup is provided a control means for driving with overlapping a predetermined time by the. Therefore, in the normal case where the input voltage from the commercial AC power supply is higher than the set voltage, the first
When the switching element is in an active state, the load is driven by an output from one or more AC-side power supply circuits, and in the case of an abnormality such as a power failure in which the input voltage from the commercial AC power supply is lower than a set voltage, the input is performed. The input voltage detection circuit detects that the voltage has dropped, and outputs a power failure signal after a predetermined time, so that the first switching element is in a stopped state. That is, the load can be continuously driven by the discharge of the capacitor until the power failure signal is output and the first switching element is stopped. The output of the backup power supply circuit is increased to a predetermined value at which the load can be driven stably by setting the second switching element to the active state while the load can be driven by discharging by the capacitor. be able to. The first switching element of the AC side power supply circuit is kept stopped by the power failure signal, and when the input voltage from the commercial AC power supply becomes equal to or higher than a set voltage, the power failure signal is not output, so that the first switching element is activated. .
At this time, since the second switching element maintains the active state, power is supplied from the backup power supply circuit to the load until the voltage of the AC power supply circuit becomes higher than the voltage of the backup power supply circuit. After a lapse of a predetermined time, the second switching element is stopped, and the load is driven only by the power from the AC side power supply circuit.

The length of the predetermined time during which the AC power supply circuit and one or a plurality of backup power supply circuits are driven redundantly is set longer than when the input voltage from the commercial AC power supply falls below a set voltage. It is set to be longer when the input voltage exceeds the set voltage. That is,
The capacitor according to claim 1 requires a very long accumulation time for accumulating electric charges from a time when the capacitor is completely discharged to a set voltage that can be stably supplied to the load. Is set for a predetermined time period for driving.

When the backup power supply circuit is a DC power supply circuit, an auxiliary power supply circuit for constantly charging the DC power supply circuit with an input voltage from the commercial AC power supply is provided, so that the power supply circuit can be connected to an outlet. If the plug for the power supply is inserted, the DC power supply circuit can be constantly charged.

[0008]

FIG. 1 shows an uninterruptible switching regulator. The uninterruptible switching regulator includes an AC power supply circuit A for rectifying AC from a commercial AC power supply 1 and outputting the rectified AC power to a primary winding N1 of a high frequency transformer 2, and a secondary winding of the high frequency transformer 2. N
2 and electrically connected to a load 3
A secondary side DC output circuit B for supplying DC power to the
DC as a backup power supply circuit for supplying power to the secondary DC output circuit B by the output of the secondary battery 4 to the tertiary winding N3 of the high-frequency transformer 2 according to the operation state of the power circuit A And the side power supply circuit C. As the secondary battery 4, a fuel cell, a solar battery, a nuclear battery, or the like may be used, and a generator or the like may be used instead of the secondary battery 4. As the uninterruptible switching regulator, besides the forward type, there are a flyback type, a full bridge type, a half bridge type and the like, and any type may be used. FIG. 1 shows a case in which one AC-side power supply circuit A and one DC-side power supply circuit C are provided so as to provide the simplest circuit. ), Or both circuits A and C may be provided with two or more (plural) circuits.

The AC-side power supply circuit A includes a rectifier circuit 5 for rectifying AC from the commercial AC power supply 1, an active filter circuit (which may be omitted) 6 as a circuit for preventing harmonic currents, A smoothing capacitor 7 for storing a DC voltage from the filter circuit 6; an FET 9 which is operated by a gate signal from a gate circuit 8 and is connected to a primary winding N1 of the high-frequency transformer 2; The power supply circuit C includes the backflow prevention diode 10 for preventing the backflow of the overcurrent due to the induced voltage from the power supply circuit C to the AC power supply circuit A. However, the configuration is not limited to the configuration shown in the drawing.

The DC side power supply circuit C is connected to the secondary battery 4 and a secondary winding n2 of another high frequency transformer 11 independent of the high frequency transformer 2 for charging the secondary battery 4. Charging circuit 12, AC power supply circuit A
A backflow prevention diode 13 as means for preventing backflow of an overcurrent due to an induced voltage from the power supply circuit C to the DC side power supply circuit C, is operated by a gate signal from a gate circuit 14, and is connected to a tertiary winding N3 of the high frequency transformer 2. Although it is configured by the FET 15 as a switching element, the configuration is not limited to the configuration shown in FIG. The output terminal of an auxiliary power supply circuit 16 connected to both ends of the smoothing capacitor 7 is connected to the primary winding n1 of the high-frequency transformer 11, and the tertiary winding n3 of the high-frequency transformer 11 is connected to 5V. A standby voltage generating circuit 36 is connected, and a voltage from the commercial AC power supply 1 is always applied to the high-frequency transformer 11 via the auxiliary power supply circuit 16 when a power cord (not shown) is inserted into an outlet. Therefore, the + 5S used for the wake-up function of the personal computer or the like using the voltage is set to the 5V standby voltage generation circuit 3.
6 so that it can be made. At the same time, by supplying the voltage to the charging circuit 12 connected to the secondary winding n2 of the high-frequency transformer 11, when power is not supplied to the load in a mode in which the main circuits A and C are stopped. In this configuration, the secondary battery 4 can be charged. Reference numeral 17 shown in the figure denotes a backflow prevention diode for preventing backflow from the secondary battery 4 to the charging circuit 12.

Two input voltage detecting circuits 18 and 19 are provided at one end on the output side of the rectifier circuit 5 for detecting that the input voltage from the commercial AC power supply 1 is lower than a set voltage.
Of the input voltage detection circuits 18, 19
Each output side is connected to the gate circuits 8 and 14. The first power failure detection circuit 18 connected to the one gate circuit 8 outputs a power failure signal (PF) 30 ms after the input voltage from the commercial AC power supply 1 falls below the set voltage, and simultaneously outputs the gate The circuit 8 is stopped to stop the power supply from the AC side power supply circuit A. When the input voltage from the commercial AC power supply 1 becomes equal to or higher than the set voltage and the power failure is eliminated, the output of the power failure signal (PF) is stopped, and at the same time, the gate circuit 8 is driven to drive the AC power supply circuit. The power supply from A is restarted. The second power failure detection circuit 19 connected to the other gate circuit 14 drives the gate circuit 14 15 ms after the input voltage from the commercial AC power supply 1 falls below the set voltage, and The power supply from the power supply circuit C is configured to start, and the input voltage from the commercial AC power supply 1 becomes equal to or higher than the set voltage, and 100 to 300 m from the time when the power failure is resolved.
After S, the gate circuit 14 is driven to drive the DC side power supply circuit C.
It is configured to stop the power supply from. That is, when the second input voltage detection circuit 19 detects that the input voltage from the commercial AC power supply 1 is lower than the set voltage, while the power is being supplied by the smoothing capacitor 7, The AC power supply circuit A and the DC power supply circuit C are driven in an overlapping manner for 15 ms by making the second switching element 15 active, and the input voltage from the commercial AC power supply 1 is equal to or higher than a set voltage. When the second input voltage detecting circuit 19 detects that the power supply has been changed to the normal state, the first switching element 9 is activated and the AC power supply circuit A starts supplying power.
The control unit 20 is configured to drive the AC power supply circuit A and the DC power supply circuit C in an overlapping manner for 100 to 300 mS by stopping the second switching element 15 after the elapse of 00 mS. Although the two input voltage detection circuits 18 and 19 are provided, the configuration may be such that one input voltage detection circuit drives the two gate circuits 8 and 14. In this case, it is configured to output two output signals by connecting a delay circuit or the like.

The overlap driving time of the AC side power supply circuit A and the DC side power supply circuit C at the time of the power failure is set to 15 mS, but it is optimal to set it between 20 and 30 mS in terms of power consumption (energy saving). . However, depending on the effective drive time by the smoothing capacitor 7 (discharge time until a predetermined voltage at which the load 3 can be driven), 10 to 40 m
It can be set between S and 1mS ~ 100mS
The overlapping time may be set shorter, and the shorter the overlapping time, the more advantageous in terms of power consumption (energy saving), and the longer the overlapping time, the more advantageous in terms of reliability, in which the voltage can be stably maintained. become. Further, the overlap driving time of the AC side power supply circuit A and the DC side power supply circuit C at the time of recovery from the power failure is set to 100 to 300 ms, but the effective driving start time by the smoothing capacitor 7 (becomes a predetermined voltage capable of driving the load 3). Depending on the charging time up to), another range can be set.

A specific circuit constituting the control means 20;
That is, the configuration of the second power failure detection circuit 19 is shown in FIG. That is, the voltage detection system reset IC 21 to which the input voltage from the commercial AC power is input, the electrolytic capacitor 22, the capacitor 23, the four resistors 24 to 27, the two transistors 28 and 29, and the second power failure from the constant voltage diode 30 Although the detection circuit 19 is configured, another configuration may be used. Further, the control means 20 may be constituted by software such as a program in addition to being constituted by hardware such as a circuit.

The operation of FIG. 2 will be described in conjunction with the time chart of FIG. 3. If the input voltage from the commercial AC power supply 1 drops below the set voltage (power failure) (see point a in FIG. 3), the capacitor 23, the output of the voltage detection system reset IC 21 becomes low, and the electric charge stored in the electrolytic capacitor 22 becomes the resistance 2
5 discharges. As a result, the level of the (+) potential of the electrolytic capacitor 22 decreases, so that the transistor 29 is stopped and the transistor 28 is activated, and a drive signal is output to the gate circuit 14 of the DC power supply circuit C. The drive of the DC side power supply circuit C is started (b in FIG. 3).
(Refer to the point, 15mS is the point b from the point a at which the input voltage drops below the set voltage.) When the input voltage from the commercial AC power supply 1 falls below the set voltage, the smoothing capacitor 7 discharges to supply power from the AC side power supply circuit A for 30 ms, and as shown in FIG. The power is supplied by the two circuits A and C only from the point b at which the driving of the side power supply circuit C is started to the point c at which the power supply by the AC side power supply circuit A ends, so that the higher voltage side Power supply can be performed stably. When the input voltage from the commercial AC power supply 1 becomes equal to or higher than the set voltage (duplexing), the output of the voltage detection system reset IC 21 becomes Hi, and the charging of the electrolytic capacitor 22 is started by the current determined by the resistor 24. ,
When the level of the (+) potential of the electrolytic capacitor 22 exceeds the voltage V _BE between the base and the emitter of the transistor 29 plus the Zener voltage of the constant voltage diode 30, a base current flows through the constant voltage diode 30 to the transistor 29, and the transistor 29 At the same time as the active state, the transistor 28 is stopped, and the power supply from the DC power supply circuit C is stopped. That is, the charging time of the electrolytic capacitor 22 (point 100 to 300 m
By supplying power to the two circuits A and C for S), power can be supplied stably from the higher voltage side. The electrolytic capacitor 2
The charging time of No. 2 is equal to or longer than the charging time of the smoothing capacitor 7. The setting of the charging time of the electrolytic capacitor 22 is determined by the capacitance of the electrolytic capacitor 22 and the value of the resistor 24.

As shown in FIG. 1, the secondary side DC output circuit B has a load 3 connected to a PWM switching control circuit 31 for performing constant voltage control on the load 3.
A rectifier diode 32, a commutation diode 33, a smoothing coil 34, and a smoothing capacitor 35 are connected to the secondary winding N2 of the high-frequency transformer 2 so as to supply a predetermined DC output power to the load 3. In the figure, only one secondary-side DC output circuit B is provided, but two or more (plural) circuits are provided so that a DC output power having a value different from the DC output power can be supplied. It can also be implemented. The PWM switching control circuit 31 controls the pulse width of the gate signal output from the gate circuits 8 and 14 to perform constant voltage control on the load 3 via the secondary DC output circuit B. I can do it.

In FIG. 4, one AC side power supply circuit and two backup power supply circuits, that is, an AC side power supply circuit and a DC side power supply circuit driven by an AC voltage generated by a device different from the commercial AC power supply 1 4 shows a time chart of the drive timing in the case of providing. In this case, an AC-side power supply circuit (hereinafter, referred to as a first AC-side power supply circuit) located above FIG.
When a backup AC-side power supply circuit (hereinafter referred to as a second AC-side power supply circuit) located in the middle of the above is connected to a dedicated device different from the commercial AC power supply 1 capable of independently generating an AC voltage. Is shown. Therefore, when AC operation is performed by the first AC side power supply circuit, the voltage from the commercial AC power supply 1 becomes lower than the set voltage (power failure).
And the smoothing capacitor 7 provided in the first AC side power supply circuit.
The drive of the second AC power supply circuit for backup is started until the AC operation due to the discharge of the AC power supply is stopped, and the two AC power supply circuits are overlapped by 15 mS (this value may be any value as described above). I try to drive. If you get a double
As described above, after driving the second AC-side power supply circuit for a predetermined time (100 to 300 ms, not limited to this range as described above) after the driving of the first AC-side power supply circuit is started, the driving is stopped. I have. In addition, when the second power failure shown in FIG. 4 occurs, the DC power supply circuit is used until the AC operation is stopped by the discharge of the smoothing capacitor 7 provided in the first AC power supply circuit. Although the drive of the power supply circuit is started, the order of the power supply circuit to be driven at the time of power failure may be set in any manner. As described above, as the number of power supply circuits increases, the circuit becomes more complicated, but it is advantageous in durability and reliability at the time of power failure. Further, a plurality of AC side power supply circuits may be connected to the commercial AC power supply 1, and only one of these AC side power supply circuits may be driven, or a plurality of AC side power supply circuits may be driven simultaneously.

[0017]

According to the first aspect, in a normal case, only one of the first switching elements is set to the active state, and the load is driven by the output from one or a plurality of AC side power supply circuits.
In the case of an abnormality, by driving only the other second switching element to the active state and driving the load with the output from the backup power supply circuit, it is possible to avoid the conventional power supply circuit from always running idle. Therefore, power consumption can be reduced. Moreover, when the drive is switched from the AC side power supply circuit to the backup power supply circuit or from the backup power supply circuit to the AC side power supply circuit, the load is applied with the stable voltage on the drive end side until the voltage on the drive start side becomes stable. By driving
The load can be driven stably in any situation.

According to the second aspect, the length of the predetermined time for driving the AC side power supply circuit and the backup power supply circuit redundantly is set longer than when the input voltage from the commercial AC power supply falls below the set voltage. Also, by setting the input voltage to be longer when the input voltage is equal to or higher than the set voltage, when the predetermined time is set to the same length in accordance with the longer predetermined time, the AC side power supply circuit and the backup Power supply circuit is not redundantly driven,
Power consumption can be reduced.

According to the third aspect of the present invention, when the backup power supply circuit is a DC power supply circuit, an auxiliary power supply for constantly charging the DC power supply circuit with an input voltage from the commercial AC power supply. By providing a circuit,
If the power plug is inserted into the outlet, the DC power circuit can be charged at all times. If the device is not used for a long time (the power switch is turned off)
In the state (F), the battery (secondary battery) is not completely discharged, and it is possible to control the device whose power switch is OFF by using another device or a remote switch. There are advantages that can be done.

[Brief description of the drawings]

FIG. 1 is a schematic electric circuit diagram of an uninterruptible switching regulator.

FIG. 2 is an electric circuit diagram showing a second power failure detection circuit.

FIG. 3 is a time chart illustrating timings of starting and stopping driving of the AC power supply circuit and the DC power supply circuit illustrated in FIG. 1;

FIG. 4 is a time chart showing timings of starting and stopping driving of two AC-side power supply circuits and one DC-side power supply circuit.

[Description of Signs] 1 Commercial AC power supply 2 High frequency transformer 3 Load 4 Secondary battery 5 Rectifier circuit 6 Active filter circuit 7 Smoothing capacitor 8 Gate circuit 9 FET (first switching element) 10 Backflow prevention diode 11 High frequency transformer 12 Charging circuit 13 Backflow prevention diode 14 Gate circuit 15 FET (second switching element) 16 Auxiliary power supply circuit 17 Backflow prevention diode 18,19 Input voltage detection circuit 20 Control means 21 Voltage detection system reset IC 22 Electrolytic capacitor 23 Capacitor 24 to 27 Resistance 28,29 Transistor 30 Constant voltage diode 31 PWM switching control circuit 32 Rectifier diode 33 Commutation diode 34 Smoothing coil 35 Smoothing capacitor 36 5V standby generation circuit A AC side power supply circuit B Secondary side DC output circuit C DC side power supply circuit N1, N2, N3 , n1, n2 winding

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) H02M 3/335 H02M 3/335 BF term (Reference) 5G015 GB02 HA01 HA14 JA02 JA11 JA32 JA52 5H730 AA14 AS16 AS19 AS23 BB23 BB57 BB83 CC01 CC13 CC17 DD04 EE08 EE10 EE59 FD01 FD11 FG05 XC06 XX02 XX13 XX22 XX33 XX45

Claims (3)

[Claims] 1. A rectifier circuit for rectifying an AC voltage from a commercial AC power supply, an input voltage detection circuit for detecting that an input voltage from the commercial AC power supply is lower than a set voltage, and an input voltage detection circuit for detecting the input voltage. A first switching element that can be switched between an active state and a stopped state based on a detection signal from a circuit, a capacitor for supplying power for a predetermined time when the input voltage is lower than a set voltage by the input voltage detection circuit, and the like. One or more provided AC-side power supply circuits are connected to the primary winding of a high-frequency transformer, and a rectifier and a smoothing circuit are connected to the secondary winding of the high-frequency transformer to supply DC output power to a load. Side DC output circuit,
A tertiary winding of the high-frequency transformer is connected to one or more backup power supply circuits including a second switching element or the like that can be switched between an active state and a stopped state based on a detection signal from the input voltage detection circuit. When the input voltage detection circuit detects that the input voltage from the commercial AC power supply is lower than a set voltage, the second switching element is activated during power supply by the capacitor. The AC power supply circuit and one or a plurality of backup power supply circuits are overlapped and driven for a predetermined time by setting a state, and the input that the input voltage from the commercial AC power supply has become equal to or higher than a set voltage. When the voltage detection circuit detects, a predetermined time has elapsed after the first switching element is activated and the power supply is started by the AC side power supply circuit. An uninterruptible switching regulator provided with control means for driving the AC side power supply circuit and one or more backup power supply circuits so as to be overlapped for a predetermined time by stopping the second switching element. . 2. The method according to claim 1, wherein the AC power supply circuit and one or more backup power supply circuits are overlappedly driven for a predetermined period of time, when the input voltage from the commercial AC power supply falls below a set voltage. 2. The apparatus according to claim 1, wherein the input voltage is set to be longer when the input voltage exceeds the set voltage.
Uninterruptible switching regulator as described. 3. When the backup power supply circuit is a DC-side power supply circuit, an auxiliary power supply circuit for constantly charging the DC-side power supply circuit with an input voltage from the commercial AC power supply is provided. Item 3. The uninterruptible switching regulator according to item 1 or 2.