A dual-power conversion device

Abstract

The present invention discloses a dual-power conversion device, belonging to the technical field of low-voltage electrics. The dual-power conversion device includes: a mechanical conversion switch and a short-time power supply circuit; the short-time power supply circuit includes an inverter output circuit, a control circuit, and first and second rectification circuits respectively connected to a first power supply and a second power supply. The output ends of the first and second rectification circuits are simultaneously connected to the input end of the inverter output circuit, and the output end of the inverter output circuit is connected to the output end of the mechanical conversion switch; both the first and second rectification circuits are controllable rectification circuits; the short-time power supply circuit further includes an abnormal current suppression module; in the non-conversion state, the rectification circuit connected to the current working power supply is made to be in a conducting state, and the other rectification circuit is made to be in a closed state; in the conversion state, a conducting signal is sent to the rectification circuit connected to the conversion target power supply, and a closing signal is sent to the other rectification circuit. The present invention can effectively suppress abnormal current and improve the safety and reliability of the system.

Description

Technical Field

[0001] The present invention belongs to the technical field of low-voltage electrics, and particularly relates to a dual-power conversion device. Background Art

[0002] In a power supply system, there are some important application scenarios with high requirements for continuous power supply, such as data centers, important industrial control systems, stadiums, communication systems, hotel audio systems, etc. Due to the problem of conversion speed, traditional ATSE products cannot meet the requirements of these application scenarios. For the rapid conversion requirements of specific customers, common products on the market currently are: UPS (zero interruption); static transfer switch STS (short interruption about 4 - 8 ms), etc. The technologies of UPS and STS are mature and are the mainstream solutions for uninterrupted (short interruption) power supply, but they are large in volume, high in cost, and high in loss.

[0003] Therefore, some manufacturers have developed a hybrid dual-power conversion device that combines a mechanical transfer switch and power electronic devices. It can not only achieve high-speed conversion but also has great advantages in terms of cost and maintenance compared with UPS and STS. Existing hybrid dual-power conversion devices usually equip a mechanical transfer switch with a short-time power supply circuit for short-time power supply to the load during the switching process of the mechanical transfer switch; the short-time power supply circuit usually adopts a circuit topology of dual-way rectification power supply, that is, power is taken from the normal and standby power supplies simultaneously and converted into a power supply voltage available for the load. The short-time power supply circuit with dual-way power supply includes an inverter output circuit, a normal rectification circuit, and a standby rectification circuit respectively connected to the normal power supply inlet end and the standby power supply inlet end of the mechanical transfer switch. The positive and negative output ends of the normal rectification circuit and the standby rectification circuit are respectively connected to the positive and negative input ends of the inverter output circuit, and the output end of the inverter output circuit is connected to the output end of the mechanical transfer switch. With this short-time power supply circuit with dual-way rectification power supply, in its standby state without conversion, since the two rectifier bridges are in parallel and the voltage amplitudes of the two power supplies usually fluctuate, it is difficult to avoid the difference in the voltage amplitudes of the two power supplies. Therefore, there is usually an abnormal current greater than 500 mA between the normal power supply and the standby power supply, and this abnormal current will cause the leakage switch on the input side to trip. Therefore, this circuit topology cannot be used in application scenarios with a leakage switch at the front stage. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the abnormal current problem existing in the existing dual-power conversion device with a short-time power supply circuit, and provide a dual-power conversion device that can effectively suppress the abnormal current and effectively improve the safety and reliability of the dual-power supply system.

[0005] The present invention specifically adopts the following technical solutions to solve the above technical problems:

[0006] A dual - power conversion device, comprising: a mechanical conversion switch for switching the power supply of a load between a first power supply and a second power supply, and a short - time power supply circuit for supplying power to the load for a short time during the switching process of the mechanical conversion switch; the short - time power supply circuit includes an inverter output circuit, a control circuit, and two rectifier circuits respectively connected to the first power supply and the second power supply: a first rectifier circuit and a second rectifier circuit. The output terminals of the first rectifier circuit and the second rectifier circuit are simultaneously connected to the input terminal of the inverter output circuit, and the output terminal of the inverter output circuit is connected to the output terminal of the mechanical conversion switch; both the first rectifier circuit and the second rectifier circuit are controllable rectifier circuits; the short - time power supply circuit further includes an abnormal current suppression module for suppressing the abnormal current generated between the first power supply and the second power supply during the power conversion process; in the non - conversion state, the abnormal current suppression module makes the rectifier circuit connected to the current working power supply in a conducting state and makes the other rectifier circuit in a closed state; in the conversion state, the abnormal current suppression module sends a conducting signal to the rectifier circuit connected to the conversion target power supply and sends a closing signal to the other rectifier circuit.

[0007] One of the preferred solutions is that the abnormal current suppression module includes a logic control module provided in the control circuit.

[0008] Further preferably, it further includes an interlock drive circuit connected to the logic control module for controlling the first rectifier circuit and the second rectifier circuit.

[0009] Even more preferably, the interlock drive circuit includes two optocouplers. The input terminals of the two optocouplers are connected to the logic control module, and the output terminals of the two optocouplers are respectively connected to the control terminals of the first rectifier circuit and the second rectifier circuit.

[0010] Another preferred solution is that the abnormal current suppression module is a drive circuit associated with the switch state of the mechanical conversion switch.

[0011] Further preferably, the drive circuit is associated with the switch state of the mechanical conversion switch through an auxiliary contact provided on the mechanical conversion switch.

[0012] Even more preferably, the drive circuit includes two optocouplers. The input terminals of the two optocouplers are connected to the auxiliary contact, and the output terminals of the two optocouplers are respectively connected to the control terminals of the first rectifier circuit and the second rectifier circuit.

[0013] Preferably, the inverter output circuit includes a DC filter circuit, a bridge circuit, and an output filter circuit connected in sequence.

[0014] Preferably, a leakage protection device is installed in the front stage of the dual - power conversion device.

[0015] Further preferably, the leakage protection device has a delay protection function, and the delay time is greater than the overall switching time of the mechanical changeover switch.

[0016] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0017] By deeply analyzing the mechanism of abnormal current generation in the existing dual-power conversion device with a short-time power supply circuit, the present invention sets the two rectifier circuits in the short-time power supply circuit as controllable rectifier circuits, and controls the on-off of the two controllable rectifier circuits through the abnormal current suppression module in the controllable rectifier circuit, effectively suppressing the generation of abnormal current, avoiding the problem of frequent tripping of the leakage protection device on the input side, and effectively improving the safety and reliability of the dual-power supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of abnormal current flowing through rectifier circuit 1 and rectifier circuit 2 simultaneously when the short-time power supply circuit of the existing dual-path rectifier power supply is in standby;

[0019] Figure 2 、 Figure 3 Schematic diagrams of abnormal current flowing only through rectifier circuit 2 and only through rectifier circuit 1 respectively when the short-time power supply circuit of the existing dual-path rectifier power supply is in standby;

[0020] Figure 4 Schematic diagram of the structural principle of a specific embodiment of the dual-power conversion device of the present invention;

[0021] Figure 5 Schematic diagram of the structural principle of another specific embodiment of the dual-power conversion device of the present invention;

[0022] Figure 6 Schematic diagram of a specific implementation circuit of the interlock drive circuit;

[0023] Figure 7 Schematic diagram of the structural principle of another specific embodiment of the dual-power conversion device of the present invention;

[0024] Figure 8 Schematic diagram of a specific implementation circuit of the drive circuit;

[0025] Figure 9 Schematic diagram of a specific structure of the inverter output circuit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] Figures 1 to 3 Shows the circuit topology of an existing hybrid dual-power conversion device, which adopts a short-time power supply circuit with dual-path rectifier power supply; as Figures 1 to 3As shown in the figure, the hybrid dual-power conversion device includes a mechanical conversion switch and a short-time power supply circuit; the input end of the short-time power supply circuit is respectively connected to the power supply A input end and the power supply B input end of the mechanical conversion switch, and the output end of the short-time power supply circuit is connected to the output end of the mechanical conversion switch; wherein, the short-time power supply circuit includes: a rectification circuit 1, a rectifier bridge 2, an inverter output circuit respectively connected to the power supply A incoming line end and the power supply B incoming line end of the mechanical conversion switch, and a control circuit for controlling the inverter output circuit; the positive output ends of the rectification circuit 1 and the rectification circuit 2 are connected to form a positive DC bus, and the negative output ends of the rectification circuit 1 and the rectification circuit 2 are connected to form a negative DC bus; an inverter output circuit is connected between the positive and negative DC buses, and the inverter output circuit is used to convert direct current into alternating current and output it to the load.

[0027] With the above circuit topology, when the short-time power supply circuit is in the standby state other than the power conversion process, there is usually an abnormal current greater than 500 mA between power supply A and power supply B. Figures 1 to 3 Several specific abnormal current paths are shown, such as Figures 1 to 3 indicated by the thick black lines in the figure. The existence of this abnormal current will, on the one hand, lead to waste of electric energy; on the other hand, if a leakage protection device is installed at the front end of the dual-power conversion device, such as a leakage switch is installed between the power supply and the mechanical conversion switch, these abnormal currents will cause the leakage switch to trip. Therefore, this circuit topology cannot be used in applications where there is a leakage switch at the front stage.

[0028] To solve this problem, the present invention proposes the following technical solutions:

[0029] A dual-power conversion device includes: a mechanical conversion switch for switching the load power supply between a first power supply and a second power supply, and a short-time power supply circuit for supplying short-time power to the load during the switching process of the mechanical conversion switch; the short-time power supply circuit includes an inverter output circuit, a control circuit, and two rectification circuits respectively connected to the first power supply and the second power supply: a first rectification circuit and a second rectification circuit, the output ends of the first rectification circuit and the second rectification circuit are simultaneously connected to the input end of the inverter output circuit, and the output end of the inverter output circuit is connected to the output end of the mechanical conversion switch; both the first rectification circuit and the second rectification circuit are controllable rectification circuits; the short-time power supply circuit further includes an abnormal current suppression module for suppressing the abnormal current generated between the first power supply and the second power supply during the power conversion process; in the non-conversion state, the abnormal current suppression module makes the rectification circuit connected to the current working power supply in the conduction state, and makes the other rectification circuit in the off state; in the conversion state, the abnormal current suppression module sends a conduction signal to the rectification circuit connected to the conversion target power supply, and sends a cut-off signal to the other rectification circuit.

[0030] The abnormal current suppression module in the above technical solution can be implemented by software, or by a hardware circuit, or by a combination of software and a hardware circuit. For the convenience of the public to understand, the technical solution of the present invention will be further described in detail below through specific embodiments and with reference to the accompanying drawings:

[0031] The basic structure of the first embodiment of the dual power supply conversion device of the present invention is as Figure 4 shown, and its basic structure is generally similar to the Figures 1 - 3 existing structure. The difference is that the rectifier circuit 1 and the rectifier circuit 2 are both controllable rectifier circuits, and a logic control module for implementing the function of the abnormal current suppression module is built in the control circuit, which can directly control the rectifier circuit 1 and the rectifier circuit 2. The working process of the dual power supply conversion device is as follows:

[0032] 1. Power-on process: When the device is powered on, the auxiliary power supply 1 and the auxiliary power supply 2 obtain power through the power supply A and the power supply B to work, and their output terminals are connected in parallel to supply power to the control circuit; the two auxiliary power supplies can ensure that only one of the power supply A or the power supply B needs to be powered on, and the control circuit can work;

[0033] 2. Non-conversion state: After the control circuit is powered on and working, it detects the contact position of the mechanical conversion switch (if there is a mechanical switch auxiliary contact, it can be realized by detecting the position of the mechanical switch auxiliary contact). If the contact position is in the power supply A closing state at this time, a control command is issued to turn on the rectifier circuit 1. At this time, the rectifier circuit 1 outputs rectified DC electrical energy to provide to the inverter output circuit. At the same time, the control circuit constantly detects the voltages of the power supply A and the power supply B. If the voltage of the circuit power supply (in this example, the power supply A) connected by the current mechanical conversion switch contact is normal, the inverter output circuit is controlled not to work and is in a standby state. In this state, the load power supply is completed by the mechanical conversion switch. The contact conduction resistance of the mechanical conversion switch is low and the energy consumption is low; while only the control circuit and the auxiliary power supply consume electrical energy in the electronic control system, and the whole system is in a very low energy consumption state;

[0034] 3. Conversion Status: During the non - conversion state of the system, if abnormal situations such as power failure of Power Supply A or voltage dip occur, when the control circuit detects abnormal voltage of the circuit power supply (Power Supply A in this example) connected to the contact of the mechanical transfer switch, it quickly controls the rectifier circuit 1 to turn off and the rectifier circuit 2 to turn on, and controls the inverter output circuit to output to the load side of the mechanical switch and controls the mechanical transfer switch to perform power supply switching; at this time, the DC electrical energy of the inverter output circuit is provided by the rectifier circuit 2. By controlling the output voltage of the inverter output circuit and assisting the mechanical transfer switch to quickly extinguish the arc, and during the conversion process of the mechanical transfer switch, electrical energy is provided to the load to reduce the power - off time of the load; after the conversion is completed, the contact of the mechanical transfer switch is in the closed state on the side of Power Supply B, and the control circuit turns off the output of the inverter output circuit and returns to the non - conversion state again. Among them, the control signals for turning off the rectifier circuit 1 and turning on the rectifier circuit 2 (or vice versa) can be carried out simultaneously or there can be a slight time difference, which will not affect the abnormal current suppression function; for example, if the rectifier circuit uses thyristors, it needs to pass through the zero - crossing point before it can be turned off.

[0035] In other embodiments, when the mechanical transfer switch switches from the side of Power Supply B to the side of Power Supply A, the control instructions received by the rectifier current 1 and the rectifier current 2 are opposite to those in the above - mentioned embodiments.

[0036] Figure 5 Shows the basic structure of the second embodiment of the dual - power - supply conversion device of the present invention. In this embodiment, the function of the abnormal current suppression module is jointly realized by the control circuit and the drive interlock circuit. A specific implementation structure of the interlock drive circuit is as Figure 6 shown, which includes optocouplers PC1 and PC2. The input ends of the optocouplers PC1 and PC2 are connected to the control circuit to receive the level signals sent by the logic control module in the control circuit. The output ends of the optocouplers PC1 and PC2 are respectively connected to the control ends of the rectifier circuit 1 and the rectifier circuit 2. The power supplies of the optocouplers PC3 and PC4 are provided by the auxiliary power supply 1 and / or the auxiliary power supply 2.

[0037] The working process of this dual - power - supply conversion device is as follows:

[0038] 1. Power - on process: When the device is powered on, the auxiliary power supply 1 and the auxiliary power supply 2 obtain power through Power Supply A and Power Supply B to work, and their output ends are connected in parallel to supply power to the control circuit; the two - way auxiliary power supply can ensure that as long as only one of Power Supply A or Power Supply B has power, the control circuit can work;

[0039] 2. Non-conversion state: After the control circuit is powered on and working, detect the contact position of the mechanical transfer switch (if there are mechanical switch auxiliary contacts, it can be achieved by detecting the position of the mechanical switch auxiliary contacts). If the contact position is in the closing state of power supply A at this time, the control circuit issues a low level for G1 (SCR) and a high level for G2 (SCR). When G1 (SCR) is at a low level and G2 (SCR) is at a high level, the optocoupler PC1 outputs a signal, and the optocoupler PC2 has no output signal, causing rectifier circuit 1 to conduct and rectifier circuit 2 to turn off. At this time, rectifier circuit 1 outputs the rectified DC electrical energy to the inverter output circuit. At the same time, the control circuit constantly detects the voltages of power supply A and power supply B. If the voltage of the circuit power supply (power supply A in this example) connected by the current mechanical transfer switch contact is normal, control the inverter output circuit not to work and be in the standby state. In this state, the load power supply is completed by the mechanical transfer switch. The contact conduction resistance of the mechanical transfer switch is low and the energy consumption is low. In the electronic control system, only the control circuit and the auxiliary power supply consume electrical energy, and the whole system is in a state of extremely low energy consumption.

[0040] 3. Conversion state: During the non-conversion state of the system, if abnormal situations such as power supply A losing power or voltage drop occur, when the control circuit detects that the voltage of the circuit power supply (power supply A in this example) connected by the current mechanical transfer switch contact is abnormal, it issues a high level for G1 (SCR) and a low level for G2 (SCR). Then, according to Figure 6 the circuit structure in, when G1 (SCR) is at a high level and G2 (SCR) is at a low level, the optocoupler PC1 has no output signal, and the optocoupler PC2 outputs a signal, causing rectifier circuit 1 to turn off and rectifier circuit 2 to conduct. And the control circuit controls the inverter output circuit to output to the load side of the mechanical switch and controls the mechanical transfer switch to perform power switching. At this time, the DC electrical energy of the inverter output circuit is provided by rectifier circuit 2. By controlling the output voltage of the inverter output circuit and assisting the mechanical transfer switch to quickly extinguish the arc, and during the conversion process of the mechanical transfer switch, provide electrical energy to the load and reduce the power-off time of the load. After the conversion is completed, the contact of the mechanical transfer switch is in the closing state on the power supply B side, and the control circuit closes the output of the inverter output circuit and returns to the non-conversion state again. Among them, the control signals for rectifier circuit 1 to turn off and rectifier circuit 2 to conduct (or vice versa) can be carried out simultaneously or there can be a slight time difference, which will not affect the abnormal current suppression function. For example, when the rectifier circuit uses thyristors, IGBTs, etc., it needs to pass through the zero-crossing point before it can be turned off.

[0041] By driving the interlock circuit, it is possible to avoid the simultaneous conduction of the two rectifier circuits, avoid the possibility of abnormal current in the standby state, and improve the system stability.

[0042] In other embodiments, when the mechanical transfer switch is switched from the B side of the power supply to the A side of the power supply, the control commands received by the rectification current 1 and the rectification current 2 are opposite to those in the above embodiments.

[0043] After adopting the dual-power conversion device in the above embodiment, there is no abnormal current in the standby state. During the conversion process, since the switching speed of the mechanical transfer switch is slower than the turn-on speed of the controllable rectification circuit, during the conversion process, when the arc on the mechanical transfer switch has not been extinguished and the rectification circuit has not been completely turned off, there may be an abnormal current for a very short time (less than the overall conversion time); or there is a certain time difference (less than the overall conversion time) between the on and off operations of the two rectification circuits, and there may also be an abnormal current during this time difference; however, since the duration of the abnormal current is less than the time required for the conversion process, for example, when a high-speed mechanical transfer switch is used, the overall switching operation time of the transfer switch is less than 50 ms, so the duration of the abnormal current is also less than 50 ms. When an input switch is provided on the input side and the input switch has a leakage detection function, it only needs to be configured as a delay leakage switch with a delay function and the delay duration is set to be greater than or equal to 50 ms to avoid the adverse effects caused by the abnormal current during the power supply conversion process.

[0044] Figure 7 The basic structure of the third embodiment is shown. The abnormal current suppression module in this embodiment is composed of a drive circuit connected to the auxiliary contact of the mechanical transfer switch. A specific implementation structure of the drive circuit is as Figure 8 shown, which includes optocouplers PC3 and PC4. The input ends of the optocouplers PC3 and PC4 are connected to the auxiliary contact to receive the level signals sent by the auxiliary contact. The output ends of the optocouplers PC3 and PC4 are respectively connected to the control ends of the rectification circuit 1 and the rectification circuit 2; among them, the level signals of the auxiliary contact, and the power supplies of the optocouplers PC3 and PC4 are provided by the auxiliary power supply 1 and / or the auxiliary power supply 2.

[0045] 1. Power-on process: When the device is powered on, the auxiliary power supply 1 and the auxiliary power supply 2 obtain power through the power supply A and the power supply B to work, and their output ends are connected in parallel to supply power to the control circuit; the two auxiliary power supplies can ensure that as long as only one of the power supply A or the power supply B is powered on, the control circuit can work;

[0046] 2. Non-conversion state: During normal power supply, the auxiliary contacts of the transfer switch send out level signals G3(SCR) and G4(SCR) according to the position state. If the mechanical transfer switch is connected to the power supply A at this time, the auxiliary contact sends out a high-level G3(SCR) and a low-level G4(SCR) signal; if the mechanical transfer switch is connected to the power supply B at this time, the auxiliary contact sends out a high-level G4(SCR) and a low-level G3(SCR) signal; According to Figure 8As can be seen from the drive circuit in [reference], when the auxiliary contact emits a high-level signal for G3 (SCR) and a low-level signal for G4 (SCR), the optocoupler PC3 outputs a signal and the optocoupler PC4 has no output, that is, the rectifier circuit 1 conducts and the rectifier current 2 is turned off; when the auxiliary contact emits a high-level signal for G4 (SCR) and a low-level signal for G3 (SCR), the optocoupler PC3 has no output and the optocoupler PC4 outputs a signal, that is, the rectifier circuit 1 is turned off and the rectifier current 2 conducts;

[0047] 3. Conversion state: During the non-conversion state of the system, if abnormal situations such as power failure of power supply A or voltage drop occur, when the control circuit detects that the voltage of the circuit power supply (power supply A in this example) connected to the contact of the mechanical transfer switch is abnormal, it controls the inverter output circuit to output to the load side of the mechanical switch and controls the mechanical transfer switch to perform power supply switching; the mechanical transfer switch starts to convert, and the state of the auxiliary contact of the mechanical transfer switch changes. At this time, the level signals G3 (SCR) and G4 (SCR) emitted by the auxiliary contact are both low levels. According to Figure 8 As can be seen from the drive circuit in [reference], at this time, both the optocoupler PC3 and the optocoupler PC4 output signals, and both the rectifier circuit 1 and the rectifier circuit 2 conduct. At this time, the DC electrical energy of the inverter output circuit is provided by the rectifier current 1 and the rectifier circuit 2 together; after the conversion is completed, the contact of the mechanical transfer switch is in the closing state on the power supply B side, and the auxiliary contact emits a high-level signal for G4 (SCR) and a low-level signal for G3 (SCR). The optocoupler PC3 has no output and the optocoupler PC4 outputs a signal, that is, the rectifier circuit 1 is turned off and the rectifier current 2 conducts; conversely, the switching from power supply B to power supply A is also based on the same principle. In this embodiment, since both the rectifier circuit 1 and the rectifier circuit 2 conduct during the conversion, there is an abnormal current during the conversion. After the conversion is completed, since the turn-off of power devices such as thyristors and IGBTs requires passing through a zero-crossing point, that is, the existence time of the abnormal current is less than or equal to the conversion time of the mechanical switch plus one current cycle of the power device; for example, when a high-speed mechanical transfer switch is used, the overall conversion operation time of the transfer switch is less than 50 ms. Therefore, the duration of the abnormal current is also less than 50 ms plus one current cycle of the power device. When an input switch is provided on the input side and the input switch has a leakage detection function, it is only necessary to configure it as a delay leakage switch with a delay function and set the delay duration to be greater than 50 ms plus one current cycle of the power device, such as 60 ms, to avoid the adverse effects caused by the abnormal current during the power supply conversion process.

[0048] Figure 9 shows a specific structure of the inverter output circuit, which includes a DC filter circuit, a bridge circuit composed of IGBTs, and an output filter circuit connected in sequence.

Claims

1. A dual power supply conversion device, comprising: A mechanical transfer switch for switching the power supply of a load between a first power supply and a second power supply, and a short-time power supply circuit for supplying power to the load for a short time during the switching process of the mechanical transfer switch; the short-time power supply circuit includes an inverter output circuit, a control circuit, and two rectifier circuits respectively connected to the first power supply and the second power supply: a first rectifier circuit and a second rectifier circuit. The output terminals of the first rectifier circuit and the second rectifier circuit are simultaneously connected to the input terminal of the inverter output circuit, and the output terminal of the inverter output circuit is connected to the output terminal of the mechanical transfer switch; characterized in that the first rectifier circuit and the second rectifier circuit are both controllable rectifier circuits; the short-time power supply circuit further includes an abnormal current suppression module for suppressing the abnormal current generated between the first power supply and the second power supply during the power supply conversion process; in the non-conversion state, the abnormal current suppression module makes the rectifier circuit connected to the current working power supply in a conducting state and makes the other rectifier circuit in a closed state; in the conversion state, the abnormal current suppression module sends a conducting signal to the rectifier circuit connected to the conversion target power supply and sends a closing signal to the other rectifier circuit.

2. The dual power supply conversion device according to claim 1, wherein The abnormal current suppression module includes a logic control module provided in the control circuit.

3. The dual power supply conversion device according to claim 2, wherein It further includes an interlock drive circuit connected to the logic control module for controlling the first rectifier circuit and the second rectifier circuit.

4. The dual-power conversion device according to claim 3, wherein The interlock drive circuit includes two optocouplers. The input terminals of the two optocouplers are connected to the logic control module, and the output terminals of the two optocouplers are respectively connected to the control terminals of the first rectifier circuit and the second rectifier circuit.

5. The dual power supply conversion device according to claim 1, wherein The abnormal current suppression module is a drive circuit associated with the switch state of the mechanical transfer switch.

6. The dual power supply conversion device according to claim 5, characterized in that, The drive circuit is associated with the switch state of the mechanical transfer switch through an auxiliary contact provided on the mechanical transfer switch.

7. The dual power supply conversion device according to claim 6, wherein The drive circuit includes two optocouplers. The input terminals of the two optocouplers are connected to the auxiliary contact, and the output terminals of the two optocouplers are respectively connected to the control terminals of the first rectifier circuit and the second rectifier circuit.

8. The dual power supply conversion device according to any one of claims 1 to 7, characterized in that, The inverter output circuit includes a DC filter circuit, a bridge circuit, and an output filter circuit connected in sequence.

9. The dual power supply conversion device according to any one of claims 1 to 7, characterized in that A leakage protection device is installed in its front stage.

10. The dual-power conversion device according to claim 9, characterized in that, The leakage protection device has a delay protection function, and the delay time is greater than the overall conversion time of the mechanical transfer switch.

Images