CN100377481C

CN100377481C - Integration converton with three phase power factor correction

Info

Publication number: CN100377481C
Application number: CNB031082548A
Authority: CN
Inventors: 李雷鸣; 应建平; 谭驚涛; 陈霖
Original assignee: Delta Optoelectronics Inc
Current assignee: Delta Optoelectronics Inc
Priority date: 2003-03-24
Filing date: 2003-03-24
Publication date: 2008-03-26
Anticipated expiration: 2023-03-24
Also published as: CN1533018A

Abstract

The present invention provides an integrated conversion device which comprises an AC/DC converter and a DC/DC converter, wherein the AC/DC converter is electrically connected with a three-phase power supply to realize the functions of converting alternating current into first direct current and correcting power factors; the DC/DC converter is electrically connected with the AC/DC converter to realize the function of converting the first direct current into second direct current. When the power is cut off, the integrated conversion device switches on a control switch to make the integrated conversion device switches from an AC/DC operation mode to a DC/DC operation mode; when the three-phase power supply resumes a normal state, the integrated conversion device switches off the control switch to make the integrated conversion device switches from the DC/DC operation mode to an AC/AC operation mode.

Description

Integrated converter with three-phase power factor correction

(1) Field of the invention

The present invention relates to a power converter, and more particularly, to a power converter implemented by using semiconductor switching devices (semiconductor switching devices) such as MOSFETs and IGBTs.

(2) Background of the invention

Fig. 1 is a block diagram of a conventional on-line three-phase input Uninterruptible Power Supply (UPS). In the figure, a three-phase alternating current/direct current (AC/DC) converter 101 and a direct current/direct current (DC/DC) converter 102 together serve as a front-end input of an inverter 103. When the three-phase power supply is normal, the control switch 104 is in an off state, the dc/dc converter 102 does not operate, and only the three-phase ac/dc converter 101 provides the dc power to the inverter 103. When the three-phase power supply is abnormal, the control switch 104 is in a conducting state, the dc/dc converter 102 works, and converts the lower voltage of the battery 105 into a suitable dc voltage to provide the dc power supply for the inverter 103. Reference numeral 107 represents the output path of the voltage or current during normal operation of the online three-phase input uninterruptible power supply system. Reference numeral 108 represents a bypass output path of the on-line three-phase input uninterruptible power supply system voltage or current. And reference numeral 109 denotes an output terminal of the uninterruptible power supply system.

In fig. 1, two sets of power conversion devices, AC/DC and DC/DC, are required for the front-end power supply of the inverter 103, so that the cost is high and the power density is low. Fig. 2 is a circuit diagram of a topology of a conventional three-phase input single-phase output UPS. In the figure ua, ub, uc represent the three-phase input power supply, N the neutral line, ia, ib, ic the three-phase input current. The AC/DC and DC/DC converter 201 is mainly composed of a rectifier circuit composed of rectifier diodes D1 to D6, a control switch S0, a battery 202, inductors L1 and L2, main switching elements S1 and S2, fast recovery diodes D7 and D8, capacitors C1 and C2, and the like. The inverter 203 is mainly composed of switching elements S3, S4. Vo represents the output voltage of the uninterruptible power supply system of the three-phase input single-phase output.

The switching element described in the present specification may be a power switch such as a MOSFET or an IGBT, and for the sake of convenience, it is referred to as a "switching element" throughout the specification, and it is referred to as a MOSFET in the drawings. It uses a half-bridge inverter as the output stage and a power converter with integrated AC/DC and DC/DC functions as the front-end input of the inverter. When the commercial power is supplied normally, the power conversion device integrating the AC/DC and DC/DC functions can cut off the change-over switch S0, and can complete the three-phase AC/DC power conversion function. When the mains supply fails, the control switch S0 is turned on, and the function of DC/DC power conversion can be completed. In the integrated conversion device, the same power element is used to realize the functions of AC/DC and DC/DC conversion under different conditions, so that the utilization rate of the power element is improved, the cost of the uninterrupted power supply is reduced, and the power density of the uninterrupted power supply is improved. However, such an integrated converter arrangement has the significant disadvantage that the AC/DC converter contained therein has little power factor correction capability. When a three-phase alternating current power supply is adopted for supplying power, the input current harmonic is very large, the total harmonic distortion rate is about 30%, the standard of each country about the input current harmonic of the electric device cannot be met, and the current application is greatly limited.

(3) Summary of the invention

The invention aims to provide an integrated conversion device with three-phase power factor correction, which can be used as the front-end input of various alternating-current uninterruptible power supplies, alternating-current emergency power supplies and the like, can realize small input current harmonic waves, meets the requirements of various standards, and has the characteristics of high efficiency, high density and low cost.

According to the idea of the invention, the integrated transformation device is characterized by comprising: one end of the inductance group is electrically connected with an alternating current power supply; the alternating current/direct current conversion device is electrically connected with the other end of the inductance group; a control switch, which is connected in series with an electric energy storage device and an inductor; and a DC/DC conversion device electrically connected to the AC/DC conversion device, wherein when the AC power supply is abnormal, the integrated conversion device turns on the control switch to convert the integrated conversion device into a first working circuit composed of the electric energy storage device, the inductor and the DC/DC conversion device, so as to provide a first DC output of the integrated conversion device, and when the AC power supply returns to normal, the integrated conversion device turns off the control switch to convert the integrated conversion device into a second working circuit composed of the inductor group, the AC/DC conversion device and the DC/DC conversion device, so as to provide a second DC output of the integrated conversion device; the DC/DC converter includes: an upper half-bridge including a first switching element, a first diode and a first capacitor; and a lower half-bridge including a second switching element, a second diode and a second capacitor; the first switch element is connected in series with the second switch element, the first diode is connected between the first switch element and the first capacitor, the second diode is connected between the second switch element and the second capacitor, the first capacitor is connected in series with the second capacitor, a node of the first switch element connected with the second switch element is directly and electrically connected with a node of the first capacitor connected with the second capacitor and is electrically connected with the neutral line of the alternating current power supply, the series circuit of the upper half bridge and the lower half bridge is connected in parallel with the series circuit of the control switch, the electric energy storage device and the inductor, when the alternating current power supply is input abnormally, the electric energy of the electric energy storage device is firstly converted and output into the first direct current, and then the first direct current is converted and output into the second direct current through the upper half bridge and the lower half bridge.

The AC/DC conversion device realizes the conversion of AC into first DC; the DC/DC conversion device realizes the function of converting the first DC into a second DC, when the AC power supply is abnormal, the integrated conversion device switches on the control switch to switch the integrated conversion device from the AC/DC operation mode to the DC/DC operation mode, when the AC power supply returns to normal, the integrated conversion device switches off the control switch to switch the integrated conversion device from the DC/DC operation mode to the AC/DC operation mode.

Preferably, the integrated transforming device further comprises a filter electrically connected between the inductor set and the ac power source.

Preferably, the ac power source abnormality is one of power failure and malfunction of the ac power source.

Preferably, the ac power source is a three-phase ac power source.

Preferably, the ac/dc converting device is a bridge rectifier.

Preferably, the electric energy storage device is a battery.

Preferably, the integrated converting apparatus includes a dc/dc converter and an ac/dc converter.

Preferably, the ac/dc converter includes the inductor set, the ac/dc conversion device, and the dc/dc conversion device.

Preferably, the integrated transforming device further comprises a sampling circuit, the sampling circuit comprising: the input end of the negative end of the operational amplifier is respectively and electrically connected with a series circuit of at least one group of resistors and diodes, the input end of the positive end of the integrated conversion device is electrically connected with a ground end, and the other end of the group of resistors is electrically connected with the alternating current power supply and is used for sampling sine waves of the alternating current power supply; and a resistor electrically connected between the negative terminal input and output of the operational amplifier.

For a more complete understanding of the objects, features and advantages of the present invention, reference should be made to the following detailed description of the preferred embodiments taken in conjunction with the accompanying drawings.

(4) Description of the drawings

FIG. 1 is a block diagram of a conventional on-line three-phase input uninterruptible power supply system;

FIG. 2 is a circuit diagram of a topology of a conventional UPS with three-phase input and single-phase output;

FIG. 3 is a circuit diagram of a power converter according to a preferred embodiment of the present invention;

FIG. 4 (a) is a simplified AC/DC converter circuit schematic of FIG. 3;

FIGS. 4 (b), (c) are schematic diagrams of the topology shown in FIG. 4 (a) broken down into completely separate upper and lower half-bridge circuits;

FIG. 5 is a schematic diagram of the simplified DC/DC converter circuit of FIG. 3;

FIG. 6 is a schematic of the control strategy of the present invention;

FIG. 7 is a schematic diagram of the operation of the AC/DC converter of the present invention;

FIG. 8 is a schematic of a three-phase input voltage waveform of the present invention;

FIG. 9 is a schematic of the present invention in a three-phase input voltage waveform;

FIG. 10 is a waveform of one of the three phases of the present invention;

FIG. 11 is a graph of voltage and current waveforms for the DC/DC converter of the present invention;

FIG. 12 is a graph of voltage and current waveforms for the DC/DC converter of the present invention; and

FIG. 13 shows a sine wave sampling circuit.

(5) Detailed description of the preferred embodiments

FIG. 3 is a circuit diagram of a power converter according to a preferred embodiment of the invention. In fig. 3, when the three-phase AC input power ua, ub, uc is normal, the control switch S0 is not conductive, and the converter can be simplified as an AC/DC converter as shown in fig. 4 (a), wherein the control switch S0 is a DC thyristor. When the three-phase ac power source ua, ub, uc fails, the DC silicon control transistor S0 is turned on, and the integrated converter of the present invention can be converted into a simplified DC/DC converter as shown in fig. 5. Therefore, the power converter of the present invention integrates the functions of both the AC/DC converter shown in fig. 4 (a) and the DC/DC converter shown in fig. 5. Since the main switching power elements S1, S2 and the fast recovery diodes D7, D8 of the AC/DC converter and the DC/DC converter are common. Therefore, the power converter has the advantages of low cost and high power density.

The AC/DC converter shown in fig. 4 (a) is mainly composed of a filter, inductors La, lb, lc, a rectifier circuit composed of rectifier diodes D1 to D6, main switching elements S1, S2, fast recovery diodes D7, D8, capacitors C1, C2 (respectively representing a first capacitor and a second capacitor described in claims), and the like.

Due to the introduction of the neutral line N, the topology shown in fig. 4 (a) can be decomposed into two completely independent partial upper and lower half-bridges shown in fig. 4 (b), (c).

Obviously, by designing the inductance of La, lb and Lc and adopting different control strategies, the circuit topology shown in fig. 4 (a) can operate in3 operation modes, i.e., continuous inductive current, discontinuous inductive current and continuous inductive current critical current. In order to operate the converter with higher efficiency and lower input current harmonics, in the integrated converter device of the present invention, a control strategy is employed such that La, lb and Lc operate in a critical current continuous operating mode. In this control mode, the on-time of the main switching elements S1 and S2 is kept constant in each input voltage cycle.

The control strategy is shown in fig. 6: the line current id1 of the upper half bridge is used to control the power element S1 to be switched on and off. The main switching element S1 is turned on when id1 reaches 0, and the main switching element S1 is turned off at the end of the on-time Ton1, the on-time Ton1 being determined by the regulator parameters. The same line current id2 of the lower half-bridge is used to control the main switching element S2 to be switched on and off. S2 is turned on when id2 reaches 0, and the main switching element S2 is turned off at the end of the on-time Ton 2. In a PFC converter, the response speed of the regulator is generally slow, and the on-time Ton of the power element is considered constant within one duty cycle (duty cycle). In addition, the time of Ton1 and Ton2 is the same.

Assuming that the three-phase input voltage is:

V _a (θ)＝V _rms sinθ

V _b (θ)＝V _rms sin(θ-120°)

V _c (θ)＝V _rms sin(θ+120°)

the PFC converter operation mode is divided into 12 phases according to the critical current continuous operation mode.

The operating principle of the PFC converter is explained below by taking θ = 0-pi/6 as an example, where V _c (θ)＞V _a (θ)＞0，V _b (θ) < 0, and id1= ia + ic, id2= -ib.

The operating waveforms of the upper half-bridge are as in fig. 7: at time t1, the inductor currents iLa, iclc of the inductors La, lc are both 0, and the main switching element S1 starts to be turned on. The inductors La and Lc start energy storage under the action of Va and Vc respectively, and inductor currents iLa and iLc increase linearly. At time t2, the on-time of the main switching element S1 equal to Ton1 is determined by the regulator parameters. At time t2, the main switching element S1 starts to turn off, and the stored inductive energy is at V ₀₁ -Va，V ₀₁ The release starts under the action of-Vc and the current iLa, iclc drops linearly. Due to V ₀₁ Va is greater than V ₀₁ -Vc, the stored energy of the inductor La is released quickly. At time t3, the current iLa reaches 0, the current iLc is not 0, and the current iLc continues to linearly decrease the energy on the inductorIs gradually released. At time t4, the current iclc reaches 0, and the energy release from the inductor is completed. The switching element is turned on again and a new switching cycle is started. As can be seen, the inductor current iLa is maintained at 0 between t3 and t 4. That is to say: in each switching cycle in the interval θ = 0-pi/6, the inductor current iLa is operated in the current discontinuous mode, and iclc is operated in the current critical continuous mode. It is clear that the input current of the C-phase will track the input voltage waveform of the C-phase well in the interval θ = 0-pi/6. The above is an operation waveform of the upper half bridge in one switching cycle at a certain time in the interval of θ = 0-pi/6.

The operating waveforms of the lower half-bridge are as follows: at time t1, bus current id2 of the lower half bridge becomes 0, and main switching element S2 starts to be turned on. The inductor Lb starts to store energy under the action of the input voltage Vb, and the inductor current iLb increases linearly. When the time t2 is reached, the on time of the main switching element S2 is equal to Ton2, the main switching element S2 starts to be cut off, the stored inductance energy starts to be released under the action of V02-Vb, and the current iLb linearly decreases. At time t3, the current iLb drops to 0, the main switching element S2 is turned on, and a new switching cycle is started. From the above analysis, it is found that the input current of the B phase in this region θ = 0-pi/6 is well-followed by the input voltage waveform of the B phase.

Similarly, the other 11 phases are also based on the phase 1 analysis, which is not described herein.

According to this strategy, the operating waveform in the interval θ = 0-pi/6 was analyzed exhaustively. It is known that the current flowing through the inductor La will have the following characteristics:

in the pi/6 to 5 pi/6 positive half cycle voltage amplitude of fig. 8, phase A is larger than that of phase B and phase C, and in the 7 pi/6 to 11 pi/6 period, the negative half cycle voltage amplitude is also larger than that of phase B and phase C, phase A is operated in the critical current continuous mode, so that the cut-off time of S1 (S2) is determined only by the input phase voltage Va. Thus ia will have an average current per switching period determined only by its phase voltage, while the voltages Vb and Vc will have no effect on it. Obviously, the input current to phase a will be a sinusoidal current that closely follows voltage Va during this period.

During the periods 0 to pi/6 (pi to 7 pi/6) and 5 pi/6 to pi (11 pi/6 to pi) of fig. 8, the off-time of the main switching element S1 (S2) is no longer determined by the input phase voltage Va, but by the phase voltages Vb and Vc, respectively. Ia thus operates in current discontinuous mode, so that the average current in each switching cycle will no longer follow the phase voltage itself, but will be determined by the voltages of the other phases. During these two periods, the input current of phase a will be distorted to some extent.

According to the above analysis, the input current of each phase completely follows its phase voltage most of the time, and is a complete sine wave, while only for a short period of time, the input current will be distorted to some extent. Therefore, a current critical continuous control strategy is employed. Fig. 9 is a simulated waveform of the input current during a cycle of the operating frequency. The topology shown in fig. 4 (a) will have a very good power factor correction function as seen from the input current waveform.

Experiments show that when the input phase voltage is 220V, the output voltage is 800V and the rated power is 5KW, the total harmonic distortion of the input current is about 7 percent, and the harmonic standard of the input current of the electric device in each country can be completely met. Fig. 10 is an input current experimental waveform of one phase in the above case.

The DC/DC converter shown in fig. 5 is mainly composed of a battery, an inductor L, main switching elements S1 and S2, fast recovery diodes D1 and D2, capacitors C1 and C2, and the like. Obviously, this converter is a typical three-level Boost converter, and its operation principle can be briefly described as follows:

the operation principle is as follows:

the converter can operate in two different regions depending on whether the input voltage is above or below half the output voltage. iL in figure 5 is the current on the inductor L,v01 and V02 are the voltages on the capacitors C1 and C2, respectively. It can generally be assumed in the analysis of the converter that the output voltage V is defined ₀ ＝V ₀₁ +V ₀₂ 。

Region 1 (Vin < Vo/2)

Referring to fig. 11, t0 is the beginning of a switching cycle when the main switching element S1 is closed, so that both power switches in the main loop are in a conducting state. As in a conventional Boost converter, the inductor L starts storing energy under the action of the input voltage Vin. At time t1, the main switching element S2 is turned off, and an inductor current iL flows through the output capacitor C2 and the diode D8 on the lower side of the circuit. Therefore, the discharge voltage applied to the inductor at this time is V ₀₂ -Vin. At time t2, i.e. at t0+ Ts/2, the main switching element S2 is switched on and the inductor L is again charged by the input voltage. At time t3, the main switching element S1 is turned off and inductor current iL will flow through D7, C1 and S2, again at V ₀₂ The action of Vin starts the discharge. Since the inductor L current alternately charges the capacitors C1 and C2 during one cycle, the voltages on the capacitors C1 and C2 can be easily controlled as long as the times t1 and t3 are controlled.

Region 2 (Vin > Vo/2)

Referring to FIG. 12, t0 is the beginning of a switching cycle, wherein the switch S1 is closed and the main switching element S2 is still turned off, the inductor current iL flows through S1, C2 and D8 at the voltage Vin-V ₀₂ An inductive current iL is established. At time t1, the main switching element S1 is turned off, forcing inductor current iL to flow through D7, C1, C2 and D8, such that inductor current iL will decrease as a function of voltage V0-Vin. In the next half cycle, the main switching element S2 will repeat the above behavior.

From the above operating mechanism it can be seen that: the operating frequency of the inductor current is twice the operating frequency of the switching element, so that the size of the inductor can be reduced.

The operating principles of AC/DC and DC/DC converters have been described previously. In the following it will be explained how the integrated converter device of the invention switches between AC/DC and DC/DC modes of operation as shown in fig. 3.

For convenience of explanation, it is first assumed that the three-phase AC power supply has been powered down and that at the instant of power down, the integrated converter device needs to switch from AC/DC mode of operation to DC/DC mode of operation. At this time, a signal is added to the gate of the direct current silicon control tube S0 to conduct the direct current silicon control tube S0, and the pulse signal generated by the PFC controller is blocked, so that only the pulse generated by the DC/DC controller is directly applied to the power switches S1 and S2, and the integrated power converter of the invention is operated in a mode of a DC/DC converter.

When the three-phase alternating current power supply is recovered to be normal, the integrated conversion device needs to be switched from the DC/DC working mode to the AC/DC working mode. In this case, in order to reliably turn off the DC scr S0, on one hand, the control signal applied to the gate of the DC scr S0 needs to be removed, and on the other hand, the pulse signals generated by the PFC controller and the DC/DC controller are blocked for a period of time, i.e., the switching elements S1 and S2 are simultaneously turned off for a period of time, which will ensure that the energy stored in the inductor L is released completely under the action of the voltage Vin-V0, so that the current in the inductor L returns to zero, and the DC scr is reliably turned off. At this point, the main loop of the integrated controller has been converted to the topology shown in FIG. 4 (a). And then the pulse signal generated by the PFC controller is directly applied to the power switches S1 and S2, so that the integrated conversion device disclosed by the invention is operated in the working mode of the AC/DC converter.

When the integrated conversion device works normally, when the monitoring system detects that the three-phase alternating current input power supply is normal, the direct current silicon control tube is cut off, and meanwhile, the PWM signal generated by the DC/DC controller is blocked, so that the integrated conversion device is used as an AC/DC converter and operates in a critical current continuous working mode under the action of a PFC control circuit, and the function of PFC correction is realized. When the three-phase alternating current power supply is in power failure or fails, the direct current silicon control tube is conducted, the DC/DC converter works, and the battery voltage is converted into high-voltage direct current through the DC/DC converter and is used as the front-end input of the inverter. In general, the monitoring system can ensure that the AC/DC converter and the DC/DC converter cannot operate together at the same time. According to the actual condition, the system works in a changed mode.

Obviously, the integrated conversion device has the advantages that:

the two working modes of the 1,AC/DC converter and the DC/DC converter are integrated.

2, the main circuit and the control circuit are simple.

3, since the main circuit is divided into two by the neutral line, the voltage stress of the switching element is not so high, and a MOSFET with a withstand voltage of 500V can be used.

4, when the AC/DC converter is in operation, the voltage stress on the output diode is small because there is no reverse recovery problem.

5, THD of the input current is very small, and the total harmonic content can meet the harmonic standard of each country on the electric device.

6, the efficiency of the integrated conversion device is high.

7, the integrated conversion device is particularly suitable for UPS systems with half-bridge inverters due to the existence of a neutral line at the input.

8, when the DC/DC converter works, a three-level technology can be adopted, so that the size of the inductor L is much smaller than that of the traditional inductor L.

In addition, when the integrated conversion device is realized, a simple and practical sine wave sampling circuit is also invented. The circuit can sample six-frequency-division sine waveforms required by a three-phase power grid as input, and can be ingeniously applied to the integrated conversion device. The sine wave sampling circuit is shown in fig. 13:

ua, ub, uc are the grid three-phase power supply respectively. The operational amplifier OP chip is connected to the ground line. The output of the operational amplifier OP is fed to the controller of the AC/DC converter. The working principle of the device is as follows:

the invention adopts the critical current continuous mode control when the AC/DC converter works, and has good power factor correction function. Here, a control chip of a critical current continuous mode such as ST L6561 is used. Because the chip is specially designed for single-phase input, the chip is low in power. Therefore, when the input is a three-phase power grid, the sine wave sampling circuit of the present invention is needed, as shown in fig. 13. The sampling circuit utilizes an operational amplifier OP, and the input end of the negative terminal of the operational amplifier OP is respectively and electrically connected with a series circuit of three groups of resistors (R1, R2, R3) and diodes (D1, D2, D3). And the resistor R4 is electrically connected between the negative terminal input terminal and the output terminal Pin3 of the operational amplifier OP. The working principle is described in two states as follows: (for ease of description, the half bridge is used as an example)

State 1: the current of only one phase power source ub flows through the bus on the lower half bridge, e.g., θ = 0-pi/6 id2= -ib. In this phase, the peak current on the bus follows the voltage waveform on ub. While the peak current id1= ia + ic on the upper half-bridge bus, the peak current id1 should also follow the voltage waveform Va + Vc. Consider that: va + Vb + Vc =0. The peak current id1 should also follow the voltage waveform of Vb.

Likewise, in state 2: with a two-phase supply Va on the bus, vc current flows through the bus of the lower half-bridge, e.g. (7 pi/6-pi) i _d2 ＝i _a +i _c At this stage, the peak current id2 on the bus follows Va + VcThe voltage waveform of (a). While the peak current id1= ib on the upper half-bridge bus, the peak current id1 follows the voltage waveform of Vb. Consider that: va + Vb + Vc =0. The peak current id2 should also follow the voltage waveform of Vb. Based on the above analysis:

current on bus I _d ^ref (θ) is expressed as:

here, k is a constant. In general, it can be stated that:

in (| V) _a (θ)|，|V _b (θ)|，|V _c (θ) |) takes the term with the largest value.

The sine wave sampling circuit is suitable for an input three-phase four-wire power factor converter, and not only can be used for control in a critical current mode, but also can be used in a current discontinuous mode and a current continuous mode.

In summary, the present invention provides a power conversion apparatus integrating AC/DC and DC/DC functions. The device can realize the AC/DC function by controlling the change-over switch S0 when a three-phase alternating current power supply is adopted for supplying power, and the harmonic wave of the input current is small, thereby meeting the standard of the input current harmonic wave of electric devices in various countries. When the three-phase alternating current power supply fails, the three-phase alternating current power supply can realize the DC/DC conversion function, and the battery voltage is converted into proper direct current voltage as the front stage of the inverter, so that the requirements of the uninterrupted power supply are met. In summary, the power conversion apparatus according to the present invention has the following features:

(1) The functions of AC/DC and DC/DC are integrated.

(2) The AC/DC converter and the DC/DC converter use the same power switching element, and have the characteristics of high power density and low cost.

(3) When used as an AC/DC converter, it has three-phase power factor correction function, has small input current harmonic wave, and can meet the standards of various countries on the input current harmonic wave of electric devices.

When used as a DC/DC conversion device, the size of the inductor can be much smaller due to the three-level control technique.

Therefore, the present invention can solve the disadvantages of the prior art and further achieve the purpose of research and development of the present invention.

Claims

1. An integrated transducer device, comprising:

one end of the inductance group is electrically connected with an alternating current power supply;

the alternating current/direct current conversion device is electrically connected with the other end of the inductance group;

a control switch, which is connected in series with an electric energy storage device and an inductor; and

a DC/DC conversion device electrically connected to the AC/DC conversion device, when the AC power supply is abnormal, the integrated conversion device switches on the control switch to convert the integrated conversion device into a first working circuit composed of the electric energy storage device, the inductor and the DC/DC conversion device together to provide a first DC output of the integrated conversion device, when the AC power supply returns to normal, the integrated conversion device switches off the control switch to convert the integrated conversion device into a second working circuit composed of the inductor group, the AC/DC conversion device and the DC/DC conversion device together to provide a second DC output of the integrated conversion device; the DC/DC conversion device includes:

an upper half-bridge including a first switch element, a first diode and a first capacitor; and

a lower half-bridge including a second switching element, a second diode and a second capacitor;

the first switch element is connected in series with the second switch element, the first capacitor is connected in series with the second capacitor, the first diode is connected between the first switch element and the first capacitor, the second diode is connected between the second switch element and the second capacitor, a node where the first switch element and the second switch element are connected is directly and electrically connected with a node where the first capacitor and the second capacitor are connected and is electrically connected with a neutral line of the alternating current power supply, a series circuit of the upper half bridge and the lower half bridge is connected in parallel with a series circuit of the control switch, the electric energy storage device and the inductor, and when the alternating current power supply is input abnormally, the electric energy of the electric energy storage device is firstly converted and output into a first direct current, and then the first direct current is converted and output into a second direct current through the upper half bridge and the lower half bridge.

2. The integrated converter of claim 1, further comprising a filter electrically connected between the inductor bank and the ac power source.

3. The integrated converter as claimed in claim 1, wherein the ac power anomaly is one of a power failure and a fault of the ac power.

4. The integrated conversion apparatus according to claim 1, wherein the ac power source is a three-phase ac power source.

5. The integrated converter of claim 1 wherein the ac/dc converter is a bridge rectifier.

6. The integrated conversion device of claim 1, wherein the electrical energy storage device is a battery.

7. The integrated converter device of claim 1, wherein the integrated converter device comprises a dc/dc converter and an ac/dc converter.

8. The integrated converter according to claim 7, wherein the ac/dc converter comprises the inductor set, the ac/dc converting device, and the dc/dc converting device.

9. The integrated converting device of claim 1, further comprising a sampling circuit, the sampling circuit comprising:

the input end of the negative end of the operational amplifier is respectively and electrically connected with a series circuit of at least one group of resistors and diodes, the input end of the positive end of the operational amplifier is electrically connected with a ground end, and the other end of the group of resistors is electrically connected with the alternating current power supply to sample sine waves of the alternating current power supply; and

and the resistor is electrically connected between the negative end input end and the output end of the operational amplifier.