CN101075746A - Uninterruptible power supply system with low power consumption - Google Patents

Abstract

An uninterruptible power supply system, comprising: a controller; a first switching switch group; a second change-over switch group; the first winding coil of the transformer is electrically connected with the load and the first change-over switch set, and the second winding coil is electrically connected with the second change-over switch set; an energy storage device; an energy feedback circuit; the DC-DC converter boosts the DC voltage output by the energy storage device; the converter converts the boosted direct-current voltage into a first alternating-current voltage and transmits the first alternating-current voltage to the first winding coil; in the power supply mode of the energy storage device, the second winding coil responds to the first alternating voltage to induct and output a second alternating voltage, so that the second alternating voltage responds to the connection state between the second selector switch group and the second winding coil to adjust the value of the first alternating voltage transmitted to the load, and the voltage required by the operation of the load is met. Therefore, the invention reduces the energy loss of the converter, reduces the use of a heat dissipation device, improves the efficiency of the converter and integrally reduces the volume of the transformer.

Description

Uninterruptible power supply system with low power consumption

technical field

The invention relates to a power supply system, in particular to an uninterrupted power supply system with low power consumption.

Background technique

An uninterruptible power supply system (Uninterruptible Power Supply, UPS) is a device connected between a power supply and a load. The power supply can be directly a commercial ACpower supply or a converted alternating current (AC) , the main purpose of the uninterruptible power supply system is to provide the energy required for the load operation in an emergency when the power supply is abnormal, so as to ensure the normal operation of the load.

Please refer to Fig. 1(a), which is a schematic circuit diagram of a known uninterruptible power supply system. As shown in the figure, the uninterruptible power supply system mainly includes a battery charger 10, a battery module 11, a DC-DC converter 12, and a converter (inverter) 13 and switch group 16 are used to transmit the voltage of the mains power supply 15 to the load 14 or to transmit the voltage stored inside the battery module 11 to the load 14 after being converted when the mains power supply 15 is abnormal, wherein , the battery charger 10 includes a transformer 101 , a rectifier 102 , a filtering device 103 , a voltage regulator 104 , a switch 105 , a CPU, and a current limiting device 106 .

When the commercial power supply 15 supplies power normally, the CPU will control the switch group 16 to be electrically connected to the commercial power supply 15 so that the AC voltage Vin is transmitted to the load 14 to provide the voltage required for the load 14 to operate. The AC voltage Vin will also be sent to the transformer 101 of the battery charger 10 for step-down operation to convert to an AC voltage with a lower voltage, and the AC voltage is converted to a DC voltage through the rectifier 102, and the DC voltage needs to be passed through The filtering device 103 filters out high frequency components of the DC voltage converted by the rectifier 102 to obtain a stable DC voltage V1.

The voltage regulator 104 is electrically connected to the switch 105 controlled by the CPU to adjust the voltage input to the battery module 11, and the current limiting device 106 is electrically connected to the output end of the voltage regulator 104 and the input end of the battery module 11 for use in to limit the maximum charge current.

Conversely, when the mains power supply 15 cannot supply power normally, the CPU will control the switching switch group 16 to close, and the battery module 11 will provide power instead, and the DC voltage V2 output by the battery module 11 will be boosted by the DC-DC converter 12, And transmit it to the converter 13 , and the converter 13 is mainly used to convert the DC voltage into an AC voltage, and then transmit it to the load 14 .

Generally speaking, the AC voltage waveform output by the converter 13 of the uninterruptible power supply system in the battery power supply mode is usually a square wave or a sine wave. Please refer to FIG. 1(b), which is a schematic diagram of the internal circuit structure of the converter shown in FIG. 1(a). As shown in the figure, one end of the converter 13 is coupled to the DC-DC converter 12, and the other One end is coupled to the load 14 , wherein the load 14 includes a load resistor 141 and a load capacitor 142 , generally speaking, the load 14 has a capacitive element, because the load 14 is a rectifying load.

The converter 13 includes four switches S1 , S2 , S3 and S4 , and each switch is mainly composed of metal oxide semiconductor field effect transistor (MOSFET) elements. Fig. 1(c) provides the switching timing diagram of the switches S1, S2, S3 and S4, mainly by controlling the switching modes of the switches S1, S2, S3 and S4 to generate a load resistance 141 across the load 14 and a load capacitance 142. The output waveform of the AC voltage Vout.

The switching mode of the switches S1, S2, S3 and S4 adopts the switching mode of the positive half cycle and the negative half cycle. For example, in the positive half cycle from t0 to t1, S1 and S4 are controlled to be turned on, and S2 and S3 are turned off, while t2 to t3 The negative half cycle controls S1 and S4 to turn off S2 and S3 to turn on, thereby generating an AC voltage Vout across the load resistor 141 and load capacitor 142 of the load 14, because the converter 13 alternately switches between the positive half cycle and the negative half cycle Therefore, the voltage across the load resistor 141 and the load capacitor 142 must be zero when the positive half cycle turns to the negative half cycle or the negative half cycle turns to the positive half cycle, so that the switching loss of the converter 13 ( switching loss) is minimized, but the switching mode of the switching switches S1, S2, S3 and S4 of the converter 13 will cause the load capacitor 142 to charge and discharge during each half cycle of the AC voltage, so the positive half cycle turns to the negative half cycle When the cycle or the negative half cycle is turned into the positive half cycle, if the resistance value of the load resistor 141 is too large, the load capacitor 142 will be discharged so that the AC voltage Vout cannot be returned to zero, and the known solution is between the positive half cycle and the negative half cycle. Between t1 to t2, t3 to t4, the switches S1 and S3 or S2 and S4 are turned on, and Fig. 1(c) turns on the switches S2 and S4, so that the load capacitor 142 and the switches S2 and A loop is formed between S4 to consume the electric energy stored in the load capacitor 142 through the switching switches S2 and S4.

However, a large amount of power will be lost in this way, and the temperature of the switches S1, S2, S3, and S4 will increase, so a large-area heat dissipation device is required to be attached to the switches, and the consumed energy will cause the converter 13 to Efficiency is reduced, thereby reducing the usage time of the battery module 11 .

Please refer to FIG. 2 , which is a schematic circuit diagram of another known uninterruptible power supply system. As shown in the figure, the uninterruptible power supply system mainly includes a first switch group 21, a transformer 22, a rectifier 23, a filter device 24, and a voltage regulator. 25, switch 26, CPU, current limiting device 27, battery module 28, converter 29, second switch group 30 and RC circuit 31, in order to transmit the voltage of the mains power supply 32 to the load 33 or the current market When the electric power source 32 is abnormal, the voltage stored inside the battery module 28 is converted and transmitted to the load 33, wherein the transformer 22 is composed of a first winding coil N1, a second winding coil N2, a third winding coil N3 and a fourth winding coil N3. The wound coil N4 is formed, and the load 33 includes a load resistor 331 and a load capacitor 332 .

When the mains power supply 32 supplies power normally, the CPU will control the switch group 21 to be electrically connected to the mains power supply 32, so that the AC voltage Vin is transmitted to the load 33 and the first winding coil N1 of the transformer 22. At this moment, the first winding coil N1 N1 is the main coil, while the second coil N2, the third coil N3 and the fourth coil N4 are secondary coil groups, and the AC voltage Vin received by the first coil N1 will be transferred through electromagnetic exchange To the auxiliary coil group, that is, the second wound coil N2 outputs a voltage V2 and the third wound coil N3 outputs a voltage V3.

The second winding coil N2 has the effect of automatic voltage adjustment, and mainly adjusts the voltage transmitted to the load 33 by being connected with the second switching switch group 30, so as to meet the predetermined voltage required for the operation of the load 33, which can avoid the voltage transmitted to the load 33. The AC voltage of the load 33 is too low or too high to affect the operation of the load 33 .

The voltage V3 output by the third winding coil N3 charges the battery module 28 through the battery charging circuit composed of the rectifier 23, the inductor L, the filter device 24, the voltage regulator 25, the switch 26, and the current limiting device 27, Among them, the inductance L is an optional component. The above-mentioned rectifier 23, filtering device 24, voltage regulator 25, switch 26, and the circuit design principle of the current limiting device 27 and the purpose and beneficial effect that can be achieved have been described in detail in the description of above-mentioned Fig. 1 (a), therefore No longer.

Conversely, when the mains power supply 32 cannot supply power normally, the CPU will control the switch group 21 to close, and the battery module 28 will provide power instead, and the DC voltage output by the battery module 28 will be sent to the converter 29 to convert it into an AC voltage , and transmitted to the fourth winding coil N4 of the transformer 22, and the AC voltage received by the fourth winding coil N4 will be transferred to the first winding coil N1 and the second winding coil N2 through electromagnetic exchange and boosted , and the voltage induced by the first winding coil N1 is mainly used to provide the voltage required for the operation of the load 33, and the voltage induced by the second winding coil N2 is connected to the second switch group 30 through the second winding coil N2 The voltage transmitted to the load 33 is adjusted in a manner to avoid affecting the operation of the load 33 due to the transmission voltage being too low or too high.

Although the circuit shown in Figure 2 can solve the problem of Figure 1(a) due to the temperature rise of the switches S1, S2, S3 and S4 of the converter, a large-area heat dissipation device is required to be attached to the switch, and it cannot be dynamically controlled by itself. The problem of adjusting the voltage delivered to the load, however, the circuit structure of the uninterruptible power supply system shown in Figure 2 uses the transformer 22 as the output converter when the mains cannot supply power normally, and how much is the winding time of the coil of the transformer 22 There is a phenomenon of excitation leakage inductance, so when the switch (not shown) included in the converter 29 is switched from on to off, the transformer 22 will release the excitation leakage inductance energy, that is, the first winding coil N1 The output voltage of the output voltage will produce a momentary spike (spike), and the known solution is to arrange an RC circuit 31 at both ends of the first wound coil N1 to eliminate the momentary spike generated by the output voltage, but the effect of its operation is not ideal.

In addition, since the known technology uses the transformer 22 as a step-up output current device when the mains power supply 32 cannot supply power normally, the fourth winding coil N4 must be able to withstand relatively large current changes, so a thicker copper wire must be used to wind it. The fourth winding coil N4 is made. In this way, the volume of the entire transformer 22 will be very large, and the copper wire will lose a large amount of power during operation, which will cause the disadvantages of poor operating efficiency of the entire uninterruptible power supply system.

Therefore, how to develop an uninterruptible power supply system that can improve the deficiencies of the above known technologies is an urgent problem to be solved at present.

Contents of the invention

The main purpose of the present invention is to provide an uninterruptible power supply system with low power consumption. In the power supply mode of the energy storage device, the DC voltage output by the energy storage device is boosted by a DC-DC converter, After being converted into an AC voltage, it is directly transmitted to the load and the first winding coil of the transformer, and the second winding coil of the transformer will respond to the first AC voltage transmitted to the first winding coil to induce and output a second AC voltage, so that the second AC The voltage adjusts the value of the first AC voltage transmitted to the load in response to the connection state between the second switch group and the second winding coil, and releases the electric energy stored in the capacitive element of the load through the energy feedback circuit or converts the The electric energy released by the capacitive element of the load is recovered to the energy storage device for charging, thereby solving the energy loss caused by the switching of the switch of the known converter, and a large-area heat dissipation device is required to be attached to the switch, and the transformer is bulky. During operation, the copper wire will lose a large amount of power, which makes the operating efficiency of the entire uninterruptible power supply system poor and other disadvantages.

To achieve the above purpose, a more general implementation of the present invention is to provide an uninterruptible power supply system, which is electrically connected to the mains power supply and the load, and the load has a capacitive element, the uninterruptible power supply system includes: a controller; A transfer switch group, which is electrically connected to the mains power supply and the controller; a second transfer switch group, which is electrically connected to the controller and one end of the load, and switches in response to the triggering of the controller; a transformer, whose It has a first winding coil, a second winding coil and a third winding coil, the first winding coil is electrically connected to the other end of the load and the switch group, the second winding coil is connected to the second The changeover switch group is electrically connected; the charging circuit is electrically connected with the third winding coil; the energy storage device is electrically connected with the charging circuit; the DC-DC converter is electrically connected with the energy storage device for The DC voltage output by the energy storage device is boosted; the converter is electrically connected to the DC-DC converter and the first winding coil of the transformer, and is used to convert the boosted DC voltage into a first AC voltage, and transmit it to the load; wherein, in the power supply mode of the energy storage device, the controller will control the first switching switch group to close, and the second coil will respond to the transmission to the first coil The first AC voltage induces and outputs a second AC voltage, so that the second AC voltage responds to the connection state between the second changeover switch group and the second winding coil to adjust the ratio of the first AC voltage transmitted to the load. value to match the voltage required for the load to operate.

According to the uninterruptible power supply system, the energy storage device is a storage battery.

According to the uninterruptible power supply system, wherein the controller is a central processing unit.

According to the above uninterruptible power supply system, wherein the charging circuit includes a rectifier, an energy feedback circuit, a ground terminal, an inductor, a controller, and a filtering and stabilizing circuit, which uses the AC voltage output by the third winding coil of the transformer to The energy storage device is charged.

According to the above uninterruptible power supply system, wherein the rectifier is electrically connected with the third winding coil for converting the AC voltage into a DC voltage, which includes: a first diode, a positive electrode of the first diode terminal electrically connected to one end of the third winding coil of the transformer; and a second diode, the anode of the first diode being electrically connected to the other end of the third winding coil of the transformer, and the first diode The negative end of the tube is electrically connected to the negative end of the second diode.

According to the above uninterruptible power supply system, wherein the filtering and stabilizing circuit includes a filtering device for filtering out high frequency components of the direct current voltage.

According to the above uninterruptible power supply system, wherein the filtering and stabilizing circuit further includes a voltage regulator and a switch, the voltage regulator is electrically connected to the filtering device and the switching switch, and the voltage regulator responds to the switching state of the switching switch To adjust the voltage input to the energy storage device, the switch operates in response to the control of the controller.

According to the above uninterruptible power supply system, wherein the filtering and stabilizing circuit further includes a current limiting device, which is electrically connected with the voltage regulator and the energy storage device, and used to limit the current for charging the energy storage device.

According to the above uninterruptible power supply system, wherein the converter converts the DC voltage output by the DC-DC converter into an AC voltage by alternately switching the positive half cycle and the negative half cycle, and transmits the voltage to the first Winding coil.

According to the above uninterruptible power supply system, wherein the energy feedback circuit is a switch, which is electrically connected to the rectifier and the filtering and stabilizing circuit, and is used to receive the control signal of the controller in the power supply mode of the energy storage device. trigger to switch.

According to the uninterruptible power supply system, in the power supply mode of the energy storage device, the residual voltage output by the capacitive element of the load will be transmitted to the first winding coil of the transformer, so that the third winding of the transformer A coil generates this alternating voltage.

According to the uninterruptible power supply system, the operation mode of the switch includes: between the positive half cycle and the negative half cycle of the converter, the control signal of the controller triggers the switch to connect to the ground The terminal is turned on, so that the AC voltage output by the third winding coil of the transformer is released to the ground terminal through the rectifier and the switch.

According to the uninterruptible power supply system, the operation mode of the switch includes: between the positive half cycle and the negative half cycle of the converter, the control signal of the controller triggers the switch to connect to the ground The switching action between the terminals is turned on and off, so that the AC voltage output by the third winding coil of the transformer is converted and processed by the rectifier and the filtering and stabilizing circuit, and then the storage device is charged to charge the load. The discharge voltage of the capacitive element is fed back to the energy storage device.

In order to achieve the above purpose, another relatively general implementation of the present invention is to provide an uninterruptible power supply system, which is electrically connected to an input power source and a load, and the load has a capacitive element, and the uninterruptible power supply system includes: a ground terminal; Energy storage device; DC-DC converter, which is electrically connected to the energy storage device; controller, used to generate a control signal; filter and voltage stabilization circuit, which is electrically connected to the energy storage device; transformer, which has a first winding A coil, a second wound coil and a third wound coil, the first wound coil is electrically connected to the load; a rectifier is electrically connected to the third wound coil of the transformer; a converter is connected to the DC- The DC converter is electrically connected to the first winding coil of the transformer; the energy feedback circuit is electrically connected to the rectifier, the controller, the ground terminal, and the filtering and voltage stabilizing circuit. In the power supply mode of the energy storage device, the response The switch should be switched when the control signal is triggered, so that the electric energy stored in the capacitive element of the load is transmitted to the first winding coil of the transformer, so that the third winding coil of the transformer generates a first voltage; The voltage is released to the ground terminal through the rectifier and the energy feedback circuit to release the energy of the transformer, or to charge the energy storage device after being converted and processed by the rectifier and the filtering and stabilizing circuit.

Therefore, in the uninterruptible power supply system of the present invention, the discharge voltage output by the capacitive element of the load is induced to the third winding coil of the transformer through the first winding coil of the transformer, and the third winding coil is released through the energy feedback circuit The induced voltage or the voltage induced by the third winding coil is recycled to the energy storage device for charging, which can improve the energy loss caused by the switching of the switch of the traditional converter, reduce the use of the cooling device attached to the switch and Improve the efficiency of the converter. In addition, in the power supply mode of the energy storage device, the voltage output by the energy storage device is boosted by the DC-DC converter, which can reduce the number of winding coils required by the transformer to save costs and shrink the transformer. volume, and can improve the overall operating efficiency.

Description of drawings

Fig. 1(a) is a schematic diagram of the circuit structure of a known uninterruptible power supply system.

Fig. 1(b) is a schematic diagram of the internal circuit structure of the converter shown in Fig. 1(a).

FIG. 1( c ) is a switching timing diagram of the switches S1 , S2 , S3 and S4 shown in FIG. 1( b ).

FIG. 2 is a schematic diagram of the circuit structure of another known uninterruptible power supply system.

Fig. 3(a) is a schematic diagram of the circuit structure of the uninterruptible power supply system of the preferred embodiment of the present invention.

Fig. 3(b) is a schematic diagram of the internal circuit structure of the converter shown in Fig. 3(a).

Fig. 3(c) is a switching timing diagram of the switching switches S1, S2, S3 and S4 of the converter and the energy feedback circuit.

FIG. 3( d ) is another switching timing diagram of the switching switches S1 , S2 , S3 , and S4 of the converter and the energy feedback circuit.

Wherein, the reference signs are explained as follows:

101, 22, 43 transformers 102, 23 rectifiers

103, 24, 461 filter device 104, 25, 462 voltage regulator

105, 26, 463, 16 switch 106, 27, 464 current limiting device

11, 28, 47 battery modules 10 battery chargers

12, 48 DC-DC Converter 13, 29, 44, 49 Converter

15, 32, 50 mains power supply 14, 33, 51 load

141 load resistor 142 load capacitor

21, 41 first switch group 30, 42 second switch group

31RC circuit 331, 511 resistors

332, 512 capacitive element N1 first winding coil

N2 second winding coil N3 third winding coil

N4 fourth winding coil 40 uninterruptible power supply system

451 Energy Feedback Circuit 452 Ground Terminal

D1, D2 diodes 46 filter voltage regulator circuit

47 Energy storage device L inductance

Vin, Vout AC voltage CPU central processing unit

S1, S2, S3, S4 switch

V1, V2, V3, V4, V5, V6 voltage

Detailed ways

Some typical embodiments embodying the features and advantages of the present invention will be described in detail in the ensuing description. It should be understood that the present invention can have various changes in different embodiments, all of which do not depart from the scope of the present invention, and the description and reference signs therein are used for illustration in nature and not for limiting the present invention. invention.

Please refer to Fig. 3 (a), which is a schematic diagram of the circuit structure of the uninterruptible power supply system of a preferred embodiment of the present invention. Provided voltage, the uninterruptible power supply system 40 includes a first transfer switch group 41, a second transfer switch group 42, a transformer 43, an energy storage device 47, a DC-DC converter 48, a converter 49 and a rectifier 44, an inductor L , an energy feedback circuit 451, a grounding terminal 452, a charging circuit composed of a CPU and a voltage stabilizing filter circuit 46, used to transmit the voltage of the mains power supply 50 to the load 51 or to transfer the energy storage device 47 to the load 51 when the mains power supply 50 is abnormal. The internally stored voltage is converted and sent to the load 51, wherein the load 51 has a resistor 511 and a capacitive element 512 or a rectifying element inside, and when the mains power supply 50 is abnormal, the energy storage device 47 is used instead to provide the load 51 with the power to operate. When the required voltage is reached, the capacitive element 512 inside the load 51 will output a discharge voltage.

The transformer 43 is composed of a first winding coil N1, a second winding coil N2 and a third winding coil N3, wherein the first winding coil N1 is the main coil, and the second winding coil N2 and the third winding coil The coil N3 is a secondary coil group, and when the first wound coil N1 receives an AC voltage, it will be transferred to the secondary coil group through electromagnetic exchange, that is, the second wound coil N2 and the third wound coil N3 respectively induce output voltages , and the first wire-wound coil N1 is electrically connected with the first switch group 41, the second switch group 42 and the converter 49, and the second wire-wound coil N2 has the effect of automatic voltage adjustment, mainly by switching with the second The state of the connection between the switch groups 42 is used to adjust the voltage transmitted to the load 51 to meet the predetermined voltage required for the operation of the load 51, which can prevent the operation of the load 51 from being affected by the AC voltage transmitted to the load 51 being too low or too high. The third wound coil N3 is connected to the rectifier 44 .

In this embodiment, the rectifier 44 is preferably a half-bridge or full-bridge rectifier, which is mainly used to convert the AC voltage output by the third winding coil N3 of the transformer 43 into a DC voltage, and it is composed of two diodes, The positive terminal of the first diode D1 is electrically connected to one terminal of the third coil N3 of the transformer 43 , and the positive terminal of the second diode D2 is electrically connected to the other terminal of the third coil N3 of the transformer 43 . One terminal, and the negative terminal of the first diode D1 is electrically connected to the negative terminal of the second diode D2, and is the output terminal of the rectifier 44 . The CPU is mainly used to control the operation of the energy feedback circuit 451 , the switch 463 , the converter 49 , the first switch group 41 and the second switch group 42 .

In this embodiment, the filtering and stabilizing circuit 46 includes a filtering device 461 , a voltage regulator 462 , a switch 463 and a current limiting device 464 . The energy feedback circuit 451 is a switching switch composed of transistors. Its first terminal is electrically connected to the filter device 461 and the inductor L, its second terminal is electrically connected to the CPU, and its third terminal is connected to the ground terminal 452. Its setting The switch is switched under the control of the CPU to release the energy stored in the inductor L to the filter device 461, and the filter device 461 filters out the high-frequency components of the DC voltage generated by the discharge of the inductor L to obtain a stable DC voltage V4 . Alternatively, the CPU can be set not to control the switching of the energy feedback circuit 451, so that the DC voltage output by the rectifier 44 is directly transmitted to the filter device 461 to filter out high-frequency components to obtain a stable DC voltage V4. The inductor L is used to increase the efficiency of energy feedback.

The voltage regulator 462 is electrically connected to the switch 463 controlled by the CPU to adjust the voltage input to the energy storage device 47, and the other end of the switch 463 is electrically connected to the ground terminal. When the energy storage device 47 has been charged After completion, the CPU will control the switch 463 to be turned on and the voltage regulator 462 to be turned off without charging the energy storage device 47; The current limiting circuit 464 charges the energy storage device 47 until the energy storage device 47 has been charged.

The current limiting device 464 is electrically connected to the output terminal of the voltage regulator 462 and the input terminal of the energy storage device 47 for limiting the maximum value of the charging current.

When the mains power supply 50 is abnormal and the energy storage device 47 provides the voltage required for the operation of the load 51, the DC-DC converter 48 is used to boost the DC voltage V5 output by the energy storage device 47, and the converter 49 Receive the DC voltage output by the DC-DC converter 48, convert the DC voltage into an AC voltage V6, and then transmit the converted AC voltage to the first winding coil N1 of the transformer 43, that is, the first winding coil N1 is two The voltage V1=V6 at the terminal to supply power to the load 51 .

The energy storage device 47 can be a storage battery, and the converter 49 includes four switching switches S1, S2, S3 and S4, each switching switch is mainly made of a metal oxide semiconductor field effect transistor (MOSFET) element or similar transistor element. Composition (as shown in Figure 3(b)), in the mode where the mains power supply 50 is abnormal and is powered by the energy storage device 47 inside the uninterruptible power supply system, the converter 49 passes through the positive half cycle and the negative half cycle. The AC voltage V6 is generated by controlling the switches S1, S2, S3 and S4 to alternately switch.

When the mains power supply 50 supplies power normally, the CPU will control the first switch group 41 to be electrically connected to the mains power supply 50, so that the AC voltage Vin is transmitted to the load 33 and the first winding coil N1 of the transformer 22, that is, the first winding coil N1. The voltage V1=Vin at both ends of the coil N1, the first wound coil N1 is the main coil, the second wound coil N2 and the third wound coil N3 are the auxiliary coil groups, and the AC received by the first wound coil N1 The voltage Vin will be transferred to the auxiliary coil group through electromagnetic exchange, that is, the second wound coil N2 outputs a voltage V2 and the third wound coil N3 outputs a voltage V3.

The second winding coil N2 has the effect of automatic voltage adjustment, and mainly adjusts the voltage Vout transmitted to the load 51 through the state connected to the second changeover switch group 30, so as to meet the predetermined voltage required for the operation of the load 51, which can avoid the transmission due to The AC voltage Vout to the load 51 is too low or too high to affect the operation of the load 33. For example, when the AC voltage Vin is too high compared with the predetermined voltage required for the load 51 to operate, the CPU will control the second switch group The connection relationship between 42 and the second wound coil N2 has a reduction effect, so that the voltage Vout transmitted to the load 51 is the AC voltage Vin minus the voltage V2 output by the second wound coil N2, that is, Vout=Vin- V2, so that the voltage delivered to the load 51 will not exceed the predetermined voltage required by the load 33 to operate. It should be noted that N2 is an optional element.

When the AC voltage Vin is too low compared with the predetermined voltage required for the operation of the load 51, the CPU will control the connection relationship between the second switch group 42 and the second winding coil N2 to have an additive function, so that the transmission The voltage Vout to the load 51 is the AC voltage Vin plus the voltage V2 output by the second wound coil N2, that is, Vout=Vin+V2, so that the voltage delivered to the load 51 will not be lower than the load 51 needs for operation The predetermined voltage, if the AC voltage Vin can meet the predetermined voltage required for the operation of the load 51, the CPU will control the connection relationship between the second switch group 42 and the second winding coil N2 to have no effect, so that The voltage Vout transmitted to the load 33 is only the AC voltage Vin, ie Vout=Vin.

An operating mode for charging the energy storage device 47 is described below. The voltage V3 output by the third winding coil N3 will be converted into a DC voltage by the rectifier 44, and sent to the filter device 461 through the inductor L, and the DC voltage needs to be filtered by the filter device 461 to filter out its high-frequency components to achieve stability. Of course, in order to enable the DC voltage converted by the rectifier 44 to be transmitted to the energy storage device 47 for charging, the CPU will control the energy feedback circuit 451 to be turned off so that the DC voltage can be transmitted to the filter device 461 .

After the CPU detects that the energy storage device 47 has been fully charged, the CPU will control the switch 463 to be turned on, and the DC voltage V4 will be transmitted to the ground terminal through the voltage regulator 462 and the switch 463, and the energy storage device 47 will not be charged, otherwise , the CPU will control the switch 463 to be non-conductive, and the DC voltage V4 will charge the energy storage device 47 through the voltage regulator 462 and the current limiting circuit 464 until the energy storage device 47 is fully charged.

Conversely, when the mains power supply 50 cannot supply power normally, the CPU will control the first switching switch group 41 to close, and the energy storage device 47 will provide electric energy instead, and the DC outputted by the energy storage device 47 will be converted by the DC-DC converter 48. The voltage V5 is boosted, and the converter 49 receives the DC voltage provided by the DC-DC converter 48 and converts the DC voltage into an AC voltage V6, and then transmits the converted AC voltage to the first winding coil of the transformer 43 N1, that is, the voltage V1=V6 at both ends of the first wound coil N1 to supply power to the load 51 . For example, when the AC voltage V6 is too high compared with the predetermined voltage required for the operation of the load 51, the CPU will control the connection relationship between the second switch group 42 and the second winding coil N2 to be degraded. Efficacy, the voltage Vout transmitted to the load 51 is the AC voltage V6 minus the voltage V2 output by the second wound coil N2, that is, Vout=V6-V2, so that the voltage transmitted to the load 51 will not exceed the load 33 The predetermined voltage required for operation.

When the AC voltage Vin is too low compared with the predetermined voltage required for the operation of the load 51, the CPU will control the connection relationship between the second switch group 42 and the second winding coil N2 to have an additive function, so that the transmission The voltage Vout to the load 51 is the AC voltage Vin plus the voltage V2 output by the second wound coil N2, that is, Vout=V6+V2, so that the voltage delivered to the load 51 will not be lower than the load 51 needs for operation If the AC voltage V6 can meet the predetermined voltage required for the operation of the load 51, the CPU will control the connection relationship between the second switch group 42 and the second winding coil N2 to have no effect, so that The voltage Vout transmitted to the load 33 is only the AC voltage Vin, that is, Vout=V6.

In this embodiment, the switching switches S1, S2, S3 and S4 inside the converter 49 also adopt the method of alternately switching between the positive half cycle and the negative half cycle, such as controlling the conduction of S1 and S4 during the positive half cycle from t0 to t1 And S2 and S3 are closed, and the negative half cycle from t2 to t3 controls S1 and S4 to be closed and S2 and S3 are turned on (as shown in Figure 3(c) and (d)), thereby generating an AC voltage Vout. 49 The AC voltage Vout is generated by alternately switching between the positive half cycle and the negative half cycle. Therefore, the output AC voltage Vout must be zero when the positive half cycle turns to the negative half cycle or the negative half cycle turns to the positive half cycle. The switching loss of the converter 49 is reduced, but due to the switching mode of the switches S1, S2, S3 and S4 of the converter 49, the capacitive element 512 of the load 51 is charged and discharged during each AC voltage half cycle period , so during the transition period with zero voltage between the positive half cycle and the negative half cycle or the transition period with zero voltage between the negative half cycle and the positive half cycle, the capacitive element 512 will have residual stored electric energy, so that the AC The voltage Vout cannot be returned to zero, so in the power supply mode of the energy storage device 47, the residual electric energy of the loadable capacitor 512 is lapped to the first winding coil N1, and the third winding coil N1 is controlled by controlling the switching state of the energy feedback circuit 451. The coil N3 discharges the electric energy of the capacitor 512 to the ground terminal through electromagnetic induction, so that the discharge voltage generated by the capacitive element 512 of the load 51 can be released to the ground terminal 452 or the energy can be transmitted to the energy storage device 47 for charging. The energy feedback circuit 451 There are two modes of switch control, which will be described below with the switching timing diagrams shown in FIG. 3( c ) and FIG. 3( d ).

Please refer to Fig. 3 (c) again, it is the switching timing diagram of the switching switches S1, S2, S3 and S4 of the converter and the energy feedback circuit, as shown in the figure, the positive half cycle of the converter 49 turns to the negative half cycle cycle or between the negative half cycle and the positive half cycle, that is, between t1 to t2, t3 to t4 and t5 to t6, the CPU will generate control signals to control the switching switches S1, S2, S3 and S4 of the converter 49 to all close, and The energy feedback circuit 451 is turned on, since the switches S1, S2, S3 and S4 of the converter 49 are all closed during this period, so it can be solved that the known switches S1, S2, S3 and S4 need to reduce the capacitance of the load 51 The discharge voltage output by the element 512 is consumed, causing the temperature of the switches S1, S2, S3, and S4 to rise, requiring a large-area heat dissipation device, and reducing the working efficiency of the converter. When the switching switch inside the transformer is switched from on to off, the output voltage of the first winding coil N1 of the transformer will generate a momentary spike.

In addition, since the CPU turns on the energy feedback circuit 451, a loop will be established between the load 51 and the first winding coil N1 of the transformer 43, so that the residual electric energy of the capacitive element 512 of the load 51 is transferred to the first winding coil N1 of the transformer 43. coil N1, and the third coil N3 of the transformer 43 converts the discharge voltage into an AC voltage with a lower voltage, and converts the AC voltage into a DC voltage via the rectifier 44, and the DC voltage output by the rectifier 44 will be It is transmitted to the ground terminal 452 via the energy feedback circuit 451 and then released, so the output AC voltage Vout of the converter 49 between the positive half cycle and the negative half cycle or the negative half cycle and the positive half cycle will return to zero, thereby making the converter 49 switching losses are reduced.

Please refer to Fig. 3(d) again, which is another switching timing diagram of the switching switches S1, S2, S3 and S4 of the converter and the energy feedback circuit, as shown in the figure, in the positive half cycle of the converter 49 During the negative half cycle or between the negative half cycle and the positive half cycle, that is, from t1 to t2, t3 to t4, and t5 to t6, the CPU will also control the switching switches S1, S2, S3, and S4 of the converter 49 to all be closed, and the energy feedback The circuit 451 is turned on and off to switch each other. Since the switches S1, S2, S3 and S4 of the converter 49 are all closed during this period, it is possible to solve the problem that the known switches S1, S2, S3 and S4 need to load The discharge voltage output by the capacitive element 512 of 51 is consumed, which causes the temperature of the switches S1, S2, S3 and S4 to rise and requires a large-area heat dissipation device, and will reduce the working efficiency of the converter, etc., and can also reduce When the transformer is switched from on to off due to the switching switch inside the converter, the output voltage of the first winding coil N1 of the transformer will generate a momentary spike.

In addition, since the CPU controls the energy feedback circuit 451 to switch on and off between the positive half cycle of the converter 49 and the negative half cycle or the negative half cycle to the positive half cycle, when the energy feedback circuit 451 is turned on, it will make A loop is established between the load 51 and the first winding coil N1 of the transformer 43, so that the discharge voltage output by the capacitive element 512 of the load 51 is transmitted to the first winding coil N1 of the transformer 43, and the third winding of the transformer 43 The wire coil N3 converts the residual voltage into a DC voltage with a lower voltage, and converts the DC voltage into a positive voltage through the rectifier 44. The inductance L is used to store part of the energy, which can be used to increase the efficiency of energy feedback, and the rectifier 44 The output DC voltage will be transmitted to the filter device 461 for filtering because the energy feedback circuit 451 is closed, and then processed by the voltage regulator 462 and the current limiting device 464 to charge the energy storage device 47 to charge the energy storage device 47 to charge the capacitor element 512 of the load 51. The output discharge voltage is fed back to the energy storage device 47, so the converter 49 has zero voltage during the transition period between the positive half cycle and the negative half cycle or the transition period between the negative half cycle and the positive half cycle. The output AC voltage Vout will be zero, so that the converter 49 can operate normally.

When the uninterruptible power supply system 40 of the present invention is powered by the energy storage device 47 when the mains power supply 50 cannot supply power normally, the DC voltage V5 output by the energy storage device 47 needs to be boosted by the DC-DC converter 48 first. It is transmitted to the converter 49 and converted into an AC voltage V6, and the converter 49 is directly connected to the voltage input end of the first winding coil N1 of the transformer 43, so it does not need to be boosted by the transformer 43, which can solve the problems of the known technology. A transformer is used as a step-up output current device, so a thicker copper wire must be used to wind the fourth winding coil N4, so that the volume of the entire transformer will be very large, and the copper wire will lose a lot of power during operation And make the operating efficiency of the whole uninterruptible power supply system poor and other disadvantages.

It should be noted that the voltage regulator 462 and the current limiting device 464 may be optional circuit elements. Of course, in addition to the single winding turn ratio shown in FIG. wire coil, and the size of the output voltage V2 is controlled by the state connected with the second switching switch group 30, so as to widen the range that can adjust the voltage delivered to the load 51. For example, the second wire-wound coil N2 can be wound For winding coils with 3 turns and 6 turns, when the switch of the second switch group N2 is switched to both ends of the winding coil with 3 turns, the output value of the second winding coil N2 will be A When the switch of the second switch group N2 is switched to both ends of the winding coil with 6 turns, the second winding coil N2 will output a voltage of 2A, and when the switch of the second switch group N2 When the switch is switched to both ends of the winding coil with 3+6 turns, the second winding coil N2 will output a voltage of A+2A=3A, so various voltage requirements can be provided through different connection methods . It should be noted that N2 is also an optional element in this embodiment.

To sum up, the uninterruptible power supply system of the present invention induces the discharge voltage output by the capacitive element of the load to the third winding coil of the transformer through the first winding coil of the transformer, and releases the third winding coil through the energy feedback circuit. The voltage induced by the winding coil or the voltage induced by the third winding coil is recovered to the energy storage device for charging, which can improve the energy loss caused by the switch switching of the traditional converter and reduce the heat dissipation device attached to the switch In addition, in the power supply mode of the energy storage device, the voltage output by the energy storage device is boosted by the DC-DC converter, which can reduce the number of winding coils required by the transformer to save costs And reduce the size of the transformer, and can improve the overall operating efficiency.

The present invention can be modified in various ways by those skilled in the art without departing from the protection scope of the appended claims.

Claims (14)

1. An uninterruptible power supply system, which is electrically connected to a mains power supply and a load, and the load has a capacitive element, and the uninterruptible power supply system includes: controller; a first transfer switch group, which is electrically connected to the mains power supply and the controller; a second switching switch group, which is electrically connected to the controller and one end of the load, and performs switch switching in response to the triggering of the controller; A transformer, which has a first winding coil, a second winding coil and a third winding coil, the first winding coil is electrically connected to the other end of the load and the first and second transfer switch groups, the first The two wire-wound coils are electrically connected to the second transfer switch group; a charging circuit electrically connected to the third wound coil; an energy storage device electrically connected to the charging circuit; a DC-DC converter, which is electrically connected to the energy storage device, and is used to boost the DC voltage output by the energy storage device; and a converter, which is electrically connected to the DC-DC converter and the first winding coil of the transformer, and is used to convert the boosted DC voltage into a first AC voltage and transmit it to the load; Wherein, in the power supply mode of the energy storage device, the controller will control the first switching switch group to be closed, and the second winding coil will respond to the first AC voltage transmitted to the first winding coil to inductively output the first Two AC voltages, so that the second AC voltage responds to the connection state between the second switch group and the second winding coil to adjust the value of the first AC voltage transmitted to the load, so as to meet the requirements of the load operation voltage. 2. The uninterruptible power supply system according to claim 1, wherein the energy storage device is a storage battery. 3. The uninterruptible power supply system according to claim 1, wherein the controller is a central processing unit. 4. The uninterruptible power supply system according to claim 1, wherein the charging circuit comprises a rectifier, an energy feedback circuit, a grounding terminal, an inductor, a controller, and a filtering and stabilizing circuit, and the output of the third winding coil of the transformer is The AC voltage charges the energy storage device. 5. The uninterruptible power supply system according to claim 4, wherein the rectifier is electrically connected to the third wound coil for converting the AC voltage into a DC voltage, comprising: a first diode, the positive end of the first diode is electrically connected to one end of the third winding coil of the transformer; and The second diode, the positive end of the first diode is electrically connected to the other end of the third winding coil of the transformer, and the negative end of the first diode is electrically connected to the negative end of the second diode . 6. The uninterruptible power supply system according to claim 4, wherein the filtering and stabilizing circuit comprises a filtering device for filtering out high frequency components of the DC voltage. 7. The uninterruptible power supply system according to claim 6, wherein the filtering and stabilizing circuit further comprises a voltage regulator and a switching switch, the voltage regulator is electrically connected to the filtering device and the switching switch, and the voltage regulator responds to the The switching state of the switch is used to adjust the voltage input to the energy storage device, and the switching switch operates in response to the control of the controller. 8. The uninterruptible power supply system according to claim 7, wherein the filtering and voltage stabilizing circuit further comprises a current limiting device, which is electrically connected with the voltage regulator and the energy storage device, and is used to limit the charging of the energy storage device current. 9. The uninterruptible power supply system according to claim 4, wherein the converter converts the DC voltage output by the DC-DC converter into an AC voltage by alternately switching between a positive half cycle and a negative half cycle, and sent to the first wire-wound coil. 10. The uninterruptible power supply system according to claim 4, wherein the energy feedback circuit is a switch, which is electrically connected to the rectifier and the filtering and stabilizing circuit, and is used to be controlled by the energy storage device in the power supply mode. The switch is triggered by the trigger of the control signal of the device. 11. The uninterruptible power supply system according to claim 10, wherein in the power supply mode of the energy storage device, the residual voltage output by the capacitive element of the load will be transmitted to the first winding coil of the transformer, so that the transformer A third wound coil generates this AC voltage. 12. The uninterruptible power supply system according to claim 11, wherein the operation mode of the changeover switch comprises: between the positive half cycle and the negative half cycle of the converter, the control signal of the controller triggers the The switching switch is connected to the grounding terminal, so that the AC voltage output by the third winding coil of the transformer is released to the grounding terminal through the rectifier and the switching switch. 13. The uninterruptible power supply system according to claim 10, wherein the operation mode of the changeover switch comprises: between the positive half cycle and the negative half cycle of the converter, the control signal of the controller triggers the Switching between the switching switch and the grounding terminal to switch on and off, so that the AC voltage output by the third winding coil of the transformer is converted and processed by the rectifier and the filtering and stabilizing circuit to charge the storage device, It is used to feed back the discharge voltage of the capacitive element of the load to the energy storage device. 14. An uninterruptible power supply system, which is electrically connected to an input power source and a load, and the load has a capacitive element, the uninterruptible power supply system comprising: ground terminal; energy storage device; a DC-DC converter electrically connected to the energy storage device; a controller for generating a control signal; A filtering and stabilizing circuit electrically connected to the energy storage device; a transformer having a first wound coil, a second wound coil and a third wound coil, the first wound coil being electrically connected to the load; a rectifier electrically connected to the third wound coil of the transformer; a current transformer electrically connected to the DC-DC converter and the first wound coil of the transformer; and The energy feedback circuit is electrically connected to the rectifier, the controller, the ground terminal, and the filtering and stabilizing circuit. In the power supply mode of the energy storage device, the switch is performed in response to the triggering of the control signal, so that the capacitance of the load The discharge voltage output by the element is transmitted to the first winding coil of the transformer, so that the third winding coil of the transformer generates a first voltage; The first voltage is released to the ground terminal through the rectifier and the energy feedback circuit to discharge the energy of the transformer, or to charge the energy storage device after being converted and processed by the rectifier and the filtering and stabilizing circuit.

Images