UPS rectification-to-discharge multiplexing converter and control method therefor

Abstract

A UPS rectification-to-discharge multiplexing converter and a control method therefor. The UPS rectification-to-discharge multiplexing converter comprises a rectification apparatus (100), a discharge apparatus (300), an inverter apparatus (200) and a multiplexing apparatus (400). In a mains supply mode, the rectification apparatus (100) is used for converting mains electricity into a direct-current voltage and respectively providing same to the inverter apparatus (200) and a battery power source (BAT), and the inverter apparatus (200) is used for receiving the direct-current voltage, converting same into an alternating-current voltage and outputting same; and in a battery mode, the discharging apparatus (300) is used for receiving a battery voltage and providing the battery voltage to the inverter apparatus (200), the multiplexing apparatus (400) multiplexes the rectification apparatus (100) into an auxiliary discharge apparatus for receiving the battery voltage and providing the battery voltage to the inverter apparatus (200), and the inverter apparatus (200) respectively receives the battery voltages from the discharge apparatus (300) and the rectification apparatus (100), and converts same into alternating-current voltages and outputs same. By means of the present invention, a designed-power level of an individual discharging device (300) and design pressure can be reduced, the utilization rate of a device can be increased, and the costs and the volume can be reduced.

Description

UPS rectification and discharge multiplexing converter and control method thereof

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on June 29, 2023, with application number 202310790192.X and invention name “UPS rectifier discharge multiplexing converter and its control method”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention relates to the field of uninterruptible power supply (UPS), and more particularly to a UPS rectification and discharge multiplexing converter and a control method thereof. Background Art

[0003] With the increasing demand for high-reliability electricity consumption, uninterruptible power supplies (UPS) are becoming increasingly widely used to provide customers with reliable power. Figure 1 shows a block diagram of a conventional UPS converter. As shown in Figure 1, a UPS converter typically includes a battery pack (BAT), a rectifier, an inverter, and a discharger. Mains AC (AC IN) is input from the rectifier, and the inverter outputs an AC voltage (AC OUT). In mains mode, the rectifier converts the mains AC to DC, thereby providing energy to the inverter and battery pack. In battery mode, the discharger boosts the battery pack DC voltage to the bus voltage, providing energy to the inverter. The UPS converter is more efficient in mains mode than in battery mode. This means that when the UPS converter operates on mains power, the overall losses are lower, while when operating in battery mode, the losses are higher. Therefore, higher power requirements are placed on the discharger design. Furthermore, in battery mode, the rectifier is idle, while the discharger operates at full power. As shown in FIG1 , in battery mode, the devices in the dotted line portion are not used, which results in low device utilization of the entire UPS converter, and thus significantly increases both cost and volume.

[0004] Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the shortcomings of existing UPS converters, such as low device utilization, large size, and high cost, and to provide a UPS rectifier-discharge multiplexing converter and a control method thereof. In battery mode, the rectifier device can be converted into a discharge device and connected in parallel with an independent discharge device, thereby improving device utilization, reducing the size of the discharge device, and thus reducing overall cost and size.

[0006] The technical solution adopted by the present invention to solve the technical problem is: constructing a UPS rectification and discharge multiplexing converter, including a rectification device connected to the mains, a discharge device connected to the battery power supply, an inverter device connected to both the rectification device and the discharge device, and a multiplexing device connected between the battery power supply and the rectification device;

[0007] In the mains mode, the rectifier device is used to convert the mains power into a DC voltage and provide it to the inverter device and the battery power supply respectively. The inverter device is used to receive the DC voltage and convert it into an AC voltage for output;

[0008] In battery mode, the discharge device is used to receive the battery voltage and provide the battery voltage to the inverter device. At the same time, the multiplexing device multiplexes the rectifier device to serve as an auxiliary discharge device to receive the battery voltage and provide the battery voltage to the inverter device. The inverter device receives the battery voltage from the discharge device and the rectifier device respectively and converts them into AC voltage for output.

[0009] In the UPS rectifier-discharge multiplexing converter described in the present invention, the rectifier device includes a mains relay module, a mains inductor module, a mains rectifier module, a mains switch module and a bus module;

[0010] The mains relay module, the mains inductor module, the mains rectifier module and the bus module are connected in sequence; the mains switch module is connected to the mains inductor module, the mains rectifier module and the bus module at the same time.

[0011] In the UPS rectifier-discharge multiplexing converter of the present invention, the mains relay module includes a first mains relay, a second mains relay and a third mains relay;

[0012] The mains inductor module includes a first mains inductor, a second mains inductor and a third mains inductor;

[0013] The mains rectifier module includes a first rectifier unit, a second rectifier unit and a third rectifier unit;

[0014] The mains switch module includes a first switch unit, a second switch unit and a third switch unit;

[0015] The busbar module includes a first busbar capacitor and a second busbar capacitor;

[0016] The first end of the first AC relay is connected to the first AC input end, the second end is connected to the first end of the first AC inductor, and the second end of the first AC inductor is connected to the first end of the first rectifier unit and the first end of the first switch unit;

[0017] The first end of the second AC relay is connected to the second AC input end, the second end is connected to the first end of the second AC inductor, and the second end of the second AC inductor is connected to the first end of the second rectifier unit and the first end of the second switch unit;

[0018] The first end of the third AC relay is connected to the third AC input end, the second end is connected to the first end of the third AC inductor, and the second end of the third AC inductor is connected to the first end of the third rectifier unit and the first end of the third switch unit;

[0019] The second end of the first rectifier unit, the second end of the second rectifier unit, and the second end of the third rectifier unit are respectively connected to the first end of the first bus capacitor, the second end of the first bus capacitor is connected to the first end of the second bus capacitor, and the third end of the first rectifier unit, the third end of the second rectifier unit, and the third end of the third rectifier unit are respectively connected to the second end of the second bus capacitor;

[0020] The second end of the first switch unit, the second end of the second switch unit, and the second end of the third switch unit are all connected to the second end of the first bus capacitor and the first end of the second bus capacitor, and the control end of the first switch unit, the control end of the second switch unit, and the control end of the third switch unit respectively receive corresponding control signals.

[0021] In the UPS rectifier-discharge multiplexing converter of the present invention, the mains relay module includes a first mains relay and a second mains relay;

[0022] The mains inductor module includes a first mains inductor and a second mains inductor;

[0023] The mains rectifier module includes a first rectifier unit and a second rectifier unit;

[0024] The mains switch module includes a first switch unit and a second switch unit;

[0025] The busbar module includes a first busbar capacitor and a second busbar capacitor;

[0026] The first end of the first AC relay is connected to the first AC input end, the second end is connected to the first end of the first AC inductor, and the second end of the first AC inductor is connected to the first end of the first rectifier unit and the first end of the first switch unit;

[0027] The first end of the second AC relay is connected to the second AC input end, the second end is connected to the first end of the second AC inductor, and the second end of the second AC inductor is connected to the first end of the second rectifier unit and the first end of the second switch unit.

[0028] The second end of the first rectifier unit and the second end of the second rectifier unit are respectively connected to the first end of the first bus capacitor, the second end of the first bus capacitor is connected to the first end of the second bus capacitor, and the third end of the first rectifier unit and the third end of the second rectifier unit are respectively connected to the second end of the second bus capacitor;

[0029] The second end of the first switch unit and the second end of the second switch unit are both connected to the second end of the first bus capacitor and the first end of the second bus capacitor, and the control end of the first switch unit and the control end of the second switch unit respectively receive corresponding control signals.

[0030] In the UPS rectifier-discharge multiplexing converter described in the present invention, the rectifier unit includes a first diode and a second diode, the anode of the first diode is connected to the cathode of the second diode and serves as the first end of the rectifier unit, the cathode of the first diode serves as the second end of the rectifier unit, and the anode of the second diode serves as the third end of the rectifier unit.

[0031] In the UPS rectifier-discharge multiplexing converter described in the present invention, the switch unit includes a first switch tube and a second switch tube. The control ends of the first switch tube and the second switch tube serve as the control end of the switch unit. The first end of the first switch tube serves as the first end of the switch unit. The second end of the first switch tube is connected to the first end of the second switch tube. The second end of the second switch tube serves as the second end of the switch unit.

[0032] In the UPS rectifier-discharge multiplexing converter described in the present invention, the multiplexing device includes a first multiplexing relay and a second multiplexing relay, the first end of the first multiplexing relay is connected to the second end of the first mains relay, and the second end is connected to the positive electrode of the battery power supply, and the first end of the second multiplexing relay is connected to the second end of the second mains relay, and the second end is connected to the negative electrode of the battery power supply.

[0033] In the UPS rectifying and discharging multiplexing converter of the present invention, two ends of the first multiplexing relay and the second multiplexing relay are respectively connected in parallel with a thyristor rectifier.

[0034] In the UPS rectifier-discharge multiplexing converter described in the present invention, the discharge device includes a first discharge switch tube, a second discharge switch tube, a third discharge switch tube, a first battery inductor, a second battery inductor, a first battery relay, and a second battery relay;

[0035] The control ends of the first discharge switching tube, the second discharge switching tube, and the third discharge switching tube respectively receive corresponding control signals. The first end of the first discharge switching tube is connected to the first end of the first bus capacitor, and the second end is connected to the first end of the first battery inductor and the first end of the second discharge switching tube. The second end of the second discharge switching tube is connected to the first end of the third discharge switching tube and the first end of the second battery inductor. The second end of the third discharge switching tube is connected to the second end of the second bus capacitor. The second end of the first battery inductor is connected to the positive electrode of the battery power supply via the first battery relay, and the second end of the second battery inductor is connected to the negative electrode of the battery power supply via the second battery relay.

[0036] In the UPS rectification and discharge multiplexing converter described in the present invention, the first input end of the inverter device is connected to the second end of the first bus capacitor and the first end of the second bus capacitor, the second input end is connected to the first end of the first bus capacitor, the third input end is connected to the second end of the second bus capacitor, and the output end outputs the AC voltage.

[0037] Another technical solution adopted by the present invention to solve its technical problem is to construct a control method for a UPS rectification and discharge multiplexing converter, wherein the UPS rectification and discharge multiplexing converter includes a rectification device, a discharge device, an inverter device, and a multiplexing device; the rectification device includes a first mains relay, a second mains relay, a first rectification unit, a second rectification unit, a first switch unit, a second switch unit, a first bus capacitor, and a second bus capacitor; the multiplexing device includes a first multiplexing relay and a second multiplexing relay; the discharge device includes a first discharge switching tube, a second discharge switching tube, a third discharge switching tube, a first battery relay, and a second battery relay;

[0038] The control method of the UPS rectification and discharge multiplexing converter includes:

[0039] In the mains power mode, the first mains relay and the second mains relay, as well as the first battery relay and the second battery relay are closed, the first multiplexing relay and the second multiplexing relay are opened, the first switch unit and the second switch unit are PWM modulated respectively, thereby charging the first bus capacitor and the second bus capacitor, and the first discharge switch tube and the third discharge switch tube are PWM modulated respectively, thereby charging the battery power supply;

[0040] In battery mode, the first AC power relay and the second AC power relay are disconnected, the first battery relay and the second battery relay as well as the first multiplexing relay and the second multiplexing relay are closed, the second discharge switch tube is PWM modulated to charge the first bus capacitor and the second bus capacitor, and the first switch unit and the second switch unit are PWM modulated respectively to charge the first bus capacitor and the second bus capacitor.

[0041] Another technical solution adopted by the present invention to solve its technical problem is to construct a control method for a UPS rectification and discharge multiplexing converter, wherein the UPS rectification and discharge multiplexing converter includes a rectification device, a discharge device, an inverter device, and a multiplexing device; the rectification device includes a first mains relay, a second mains relay, a third mains relay, a first rectification unit, a second rectification unit, a third rectification unit, a first switch unit, a second switch unit, a third switch unit, a first bus capacitor, and a second bus capacitor; the multiplexing device includes a first multiplexing relay and a second multiplexing relay; the discharge device includes a first discharge switching tube, a second discharge switching tube, a third discharge switching tube, a first battery relay, and a second battery relay;

[0042] The control method of the UPS rectification and discharge multiplexing converter includes:

[0043] In the mains power mode, the first mains relay, the second mains relay, and the third mains relay, as well as the first battery relay and the second battery relay, are closed, the first multiplexing relay and the second multiplexing relay are opened, the first switch unit, the second switch unit, and the third switch unit are PWM modulated respectively, thereby charging the first bus capacitor and the second bus capacitor, and the first discharge switch tube and the third discharge switch tube are PWM modulated respectively, thereby charging the battery power supply;

[0044] In battery mode, the first mains relay, the second mains relay and the third mains relay are disconnected, the first battery relay and the second battery relay as well as the first multiplexing relay and the second multiplexing relay are closed, the second discharge switch tube is PWM modulated to charge the first bus capacitor and the second bus capacitor, and the first switch unit and the second switch unit are PWM modulated respectively to charge the first bus capacitor and the second bus capacitor.

[0045] The control method of the UPS rectification and discharge multiplexing converter according to the present invention further includes:

[0046] When switching from the mains mode to the battery mode, sending a first drive signal at a first moment to drive the mains relay to close, and the contacts of the mains relay are disconnected at a second moment;

[0047] Sending a second driving signal at the second moment to drive the multiplexing relay to close, and the multiplexing relay to close at a third moment;

[0048] At the fourth moment, the switch unit performs PWM modulation in the battery mode, and the switching is completed;

[0049] The fourth moment is later than the third moment, the third moment is later than the second moment, and the second moment is later than the first moment.

[0050] The control method of the UPS rectification and discharge multiplexing converter according to the present invention further includes:

[0051] When switching from the battery mode to the mains mode, sending a third driving signal at a fifth moment to drive the multiplexing relay to close, and the contact of the multiplexing relay is disconnected at a sixth moment;

[0052] Sending a fourth drive signal at the sixth moment to drive the mains relay to close, and the mains relay to close at the seventh moment;

[0053] At the eighth moment, the switch unit performs PWM modulation in the mains mode, and the switching is completed;

[0054] The eighth moment is later than the seventh moment, the seventh moment is later than the sixth moment, and the sixth moment is later than the fifth moment.

[0055] The present invention multiplexes the rectifier device in time-sharing mode, that is, in battery mode, the rectifier device is multiplexed by the multiplexing device to serve as an auxiliary discharge device to receive the battery voltage and provide the battery voltage to the inverter device. In battery mode, the rectifier device can be multiplexed as an auxiliary discharge device to share the discharge power of the independent discharge device. Compared with the traditional uninterruptible power supply converter, the present invention can reduce the design power level of the independent discharge device, reduce the design pressure of the discharge device, improve the utilization rate of the device, and reduce the cost and volume of the UPS rectifier-discharge multiplexing converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0057] FIG1 shows a block diagram of a UPS converter in the prior art;

[0058] FIG2 is a block diagram of the UPS rectifier-discharge multiplexing converter of the present invention;

[0059] FIG3 is a circuit diagram of a preferred embodiment of a UPS rectifying and discharging multiplexing converter according to the present invention, in which the inverter device is omitted;

[0060] FIG4 is a circuit diagram of another preferred embodiment of a UPS rectifying and discharging multiplexing converter according to the present invention;

[0061] FIG5 is a circuit diagram of another preferred embodiment of the UPS rectification and discharge multiplexing converter of the present invention, in which the inverter device is omitted;

[0062] FIG6 is a circuit diagram of another preferred embodiment of the UPS rectifying and discharging multiplexing converter of the present invention, in which the inverter device is omitted;

[0063] 7A-H show the current paths of the UPS rectification and discharge multiplexing converter in different modes according to the present invention;

[0064] FIG8 shows a switching control sequence of the mains power supply and battery power supply of the UPS rectification and discharge multiplexing converter of the present invention. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0066] The present invention provides a UPS rectification and discharge multiplexing converter, comprising a rectifier connected to a mains power supply, a discharge device connected to a battery power supply, and an inverter connected to both the rectifier and the discharge device, including a multiplexing device connected between the battery power supply and the rectifier; in a mains power mode, the rectifier is used to convert the mains power into a direct current voltage and provide it to the inverter and the battery power supply, respectively; the inverter is used to receive the direct current voltage and convert it into an alternating current voltage for output; in a battery mode, the discharge device is used to receive a battery voltage and provide it to the inverter, while the multiplexing device multiplexes the rectifier as an auxiliary discharge device to receive the battery voltage and provide it to the inverter, and the inverter receives the battery voltage from the discharge device and the rectifier respectively and converts it into an alternating current voltage for output. The present invention multiplexes the rectifier device in time-sharing mode, that is, in battery mode, the rectifier device is multiplexed by the multiplexing device to serve as an auxiliary discharge device to receive the battery voltage and provide the battery voltage to the inverter device. In battery mode, the rectifier device can be multiplexed as an auxiliary discharge device to share the discharge power of the independent discharge device. Compared with the traditional uninterruptible power supply converter, the present invention can reduce the design power level of the independent discharge device, reduce the design pressure of the discharge device, improve the utilization rate of the device, and reduce the cost and volume of the UPS rectifier-discharge multiplexing converter.

[0067] Figure 2 is a block diagram of the UPS rectifier-discharge multiplexing converter of the present invention. As shown in Figure 2, the UPS rectifier-discharge multiplexing converter includes a rectifier 100 connected to the AC mains power supply (AC IN), a discharger 300 connected to the battery power supply (BAT), an inverter 200 connected to both the rectifier 100 and the discharger 300, and a multiplexing device 400 connected between the battery power supply (BAT) and the rectifier 100.

[0068] In mains mode, the rectifier 100 is used to convert the mains power AC IN into a DC voltage and provide it to the inverter 200 and the battery power supply BAT, respectively. The inverter 200 receives the DC voltage and converts it into an AC voltage, outputting AC OUT. In battery mode, the discharger 300 is used to receive the battery voltage and provide it to the inverter 200. Simultaneously, the multiplexing device 400 multiplexes the rectifier 100 as an auxiliary discharger, receiving the battery voltage and providing it to the inverter 200. The inverter 200 receives the battery voltage from the discharger 300 and the rectifier 100, respectively, and converts it into an AC voltage, outputting AC OUT.

[0069] Here, the rectifier device 100, the inverter device 200, and the discharge device 300 can be constructed using any module, chip, and circuit known in the art. In a preferred embodiment of the present invention, the rectifier device can be constructed using a Vienna rectifier. For example, the rectifier device 100 can include a mains relay module, a mains inductor module, a mains rectifier module, a mains switch module, and a bus module. The mains relay module, the mains inductor module, the mains rectifier module, and the bus module are connected in sequence; the mains switch module is simultaneously connected to the mains inductor module, the mains rectifier module, and the bus module. Similarly, the inverter device 200 and the discharge device 300 can also be constructed using any suitable inverter circuit, chip, and device.

[0070] In a preferred embodiment of the present invention, the multiplexing device 400 may include any suitable switching device, such as a switching tube, a relay, etc., which is used to connect the rectifier device as an auxiliary discharge device between the battery power supply BAT and the rectifier device 100 in battery mode, receive the battery voltage and provide the battery voltage to the inverter device 200.

[0071] The present invention multiplexes the rectifier device in time-sharing mode, that is, in battery mode, the rectifier device is multiplexed by the multiplexing device to serve as an auxiliary discharge device to receive the battery voltage and provide the battery voltage to the inverter device. In battery mode, the rectifier device can be multiplexed as an auxiliary discharge device to share the discharge power of the independent discharge device. Compared with the traditional uninterruptible power supply converter, the present invention can reduce the design power level of the independent discharge device, reduce the design pressure of the discharge device, improve the utilization rate of the device, and reduce the cost and volume of the UPS rectifier-discharge multiplexing converter.

[0072] Figure 3 is a circuit diagram of a preferred embodiment of a UPS rectifier-discharge multiplexing converter according to the present invention, in which the inverter device is omitted. As shown in Figure 3, the rectifier device 100 includes a mains relay module consisting of mains relays RLYa, RLYb, and RLYc; a mains inductor module consisting of mains inductors La, Lb, and Lc; a mains rectifier module consisting of diodes Da1, Da2, Db1, Db2, Dc1, and Dc2; a mains switch module consisting of switches Qa1, Qa2, Qb1, Qb2, Qc1, and Qc2; and a bus module consisting of bus capacitors Cp and Cn. Diodes Da1 and Da2 form a first rectifier unit, diodes Db1 and Db2 form a second rectifier unit, diodes Dc1 and Dc2 form a third rectifier unit, switches Qa1 and Qa2 form a first switch unit, switches Qb1 and Qb2 form a second switch unit, and switches Qc1 and Qc2 form a third switch unit. The mains relay module, mains inductor module, mains rectifier module, and busbar module are connected in sequence; the mains switch module is simultaneously connected to the mains inductor module, mains rectifier module, and busbar module.

[0073] Furthermore, as shown in Figure 3, the first end of the AC relay RLYa is connected to the first AC input terminal LA IN, the second end is connected to the first end of the AC inductor La, and the second end of the AC inductor La is connected to the anode of the diode Da1 and the cathode of the diode Da2 (i.e., the first end of the first rectifier unit) and the first end of the switch tube Qa1 (i.e., the first end of the first switch unit).

[0074] The first end of the mains relay RLYb is connected to the second AC input terminal LB IN, and the second end is connected to the first end of the mains inductor Lb. The second end of the mains inductor Lb is connected to the anode of the diode Db1 and the cathode of the diode Db2 (i.e., the first end of the second rectifier unit) and the first end of the switch tube Qb1 (i.e., the first end of the second switch unit).

[0075] The first end of the mains relay RLYc is connected to the third AC input terminal LC IN, and the second end is connected to the first end of the mains inductor Lc. The second end of the mains inductor Lc is connected to the anode of the diode Dc1 and the cathode of the diode Dc2 (i.e., the first end of the third rectifier unit) and the first end of the switch tube Qc1 (i.e., the first end of the third switch unit).

[0076] The cathode of diode Da1 (i.e., the second end of the first rectifier unit), the cathode of diode Db1 (the second end of the second rectifier unit), and the cathode of diode Dc1 (the second end of the third rectifier unit) are respectively connected to the first end of bus capacitor Cp. The second end of bus capacitor Cp is connected to the first end of bus capacitor Cn. The anode of diode Da2 (i.e., the third end of the first rectifier unit), the anode of diode Db2 (the third end of the second rectifier unit), and the anode of diode Dc2 (the third end of the third rectifier unit) are respectively connected to the second end of bus capacitor Cn.

[0077] The second end of the switch tube Qa2 (i.e., the second end of the first switch unit), the second end of the switch tube Qb2 (i.e., the second end of the second switch unit), and the second end of the switch tube Qc2 (i.e., the second end of the third switch unit) are all connected to the second end of the bus capacitor Cp and the first end of the bus capacitor Cn (i.e., N IN The control ends of the switch tubes Qa1 and Qa2 (i.e., the control end of the first switch unit), the control ends of the switch tubes Qb1 and Qb2 (i.e., the control end of the second switch unit), and the control ends of the switch tubes Qc1 and Qc2 (i.e., the control end of the third switch unit) respectively receive corresponding control signals.

[0078] The multiplexing device 400 includes a multiplexing relay RLY6 and a multiplexing relay RLY7. The first end of the multiplexing relay RLY6 is connected to the second end of the AC power relay RLYa, and the second end is connected to the positive electrode of the battery power supply BAT. The first end of the multiplexing relay RLY7 is connected to the second end of the AC power relay RLYb, and the second end is connected to the negative electrode of the battery power supply BAT.

[0079] The discharge device 300 includes discharge switching transistors Q7, Q8, and Q9, a battery inductor Ldc1, a battery inductor Ldc2, a battery relay RLY4, and a battery relay RLY5. The control terminals of the discharge switching transistors Q7, Q8, and Q9 receive corresponding control signals. The first terminal of the discharge switching transistor Q7 is connected to the first terminal of the bus capacitor Cp, and the second terminal is connected to the first terminal of the battery inductor Ldc1 and the first terminal of the discharge switching transistor Q8. The second terminal of the discharge switching transistor Q8 is connected to the first terminal of the discharge switching transistor Q9 and the first terminal of the battery inductor Ldc2. The second terminal of the discharge switching transistor Q9 is connected to the second terminal of the bus capacitor Cn. The second terminal of the battery inductor Ldc1 is connected to the positive terminal of the battery power supply BAT via the battery relay RLY4, and the second terminal of the battery inductor Ldc2 is connected to the negative terminal of the battery power supply BAT via the battery relay RLY5.

[0080] In the mains mode, the mains relays RLYa, RLYb, and RLYc, as well as the battery relays RLY4 and RLY5, are closed, the multiplexing relays RLY6 and RLY7 are opened, the switching tubes Qa1, Qa2, Qb1, Qb2, Qc1, and Qc2 are PWM-modulated to charge the bus capacitors Cp and Cn, and the discharge switching tubes Q7 and Q9 are PWM-modulated to charge the battery power supply BAT;

[0081] In battery mode, the mains relay RLYa, the mains relay RLYb and the mains relay RLYc are disconnected, the battery relay RLY4 and the battery relay RLY5 as well as the multiplexing relay RLY6 and the multiplexing relay RLY7 are closed, the discharge switch tube Q8 is PWM modulated to charge the bus capacitor Cp and the bus capacitor Cn, and the switch tubes Qa1, Qa2, Qb1 and Qb2 are PWM modulated respectively to charge the bus capacitor Cp and the bus capacitor Cn.

[0082] Preferably, in a preferred embodiment of the present invention, each switching tube can be constructed as a triode, with the control terminal of the switching tube being the base of the triode, the first terminal being the emitter of the triode, and the second terminal being the collector of the triode. Of course, in other preferred embodiments of the present invention, each switching tube can also be constructed as any suitable switching tube, such as a MOS tube, an IGBT tube, or the like. In further preferred embodiments of the present invention, each rectifier unit can also include a larger number of diodes, or adopt a switching tube rectifier unit structure.

[0083] In a preferred embodiment of the present invention, the battery power supply BAT is preferably two groups of batteries. Correspondingly, the battery power supply BAT can also lead to the battery midpoint and the system midpoint (i.e., N IN In battery power mode, multiplex relays RLY6 and RLY7 can be gradually switched on, thereby gradually expanding the discharge power to the maximum.

[0084] FIG4 is a circuit diagram of another preferred embodiment of a UPS rectifier-discharge multiplexing converter according to the present invention. In the preferred embodiment shown in FIG4 , a preferred inverter device is shown. The UPS rectifier-discharge multiplexing converter shown in FIG4 includes a rectifier 100 connected to the mains AC IN, a discharge device 300 connected to the battery power source BAT, an inverter 200 connected to both the rectifier 100 and the discharge device 300, and a multiplexing device 400 connected between the battery power source BAT and the rectifier 100. The structures of the rectifier 100 and the multiplexing device 400 are identical to those of the embodiment shown in FIG3 and will not be further described here.

[0085] In the preferred embodiment shown in Figure 4 , the discharge device 300 includes discharge switching transistors Q7, Q8, Q9, Q10, a battery inductor Ldc1, a battery inductor Ldc2, a battery relay RLY4, and a battery relay RLY5. Control terminals of the discharge switching transistors Q7, Q8, Q9, and Q10 receive corresponding control signals. The first terminal of the discharge switching transistor Q7 is connected to the first terminal of the bus capacitor Cp, and the second terminal is connected to the first terminal of the battery inductor Ldc1 and the first terminal of the discharge switching transistor Q8. The second end of the discharge switch tube Q8 is connected to the first end of the discharge switch tube Q9. The second end of the discharge switch tube Q9 is connected to the first end of the discharge switch tube Q10 and the first end of the battery inductor Ldc2. The second end of the discharge switch tube Q10 is connected to the second end of the bus capacitor Cn. The second end of the battery inductor Ldc1 is connected to the positive electrode of the battery power source BAT via the battery relay RLY4. The second end of the battery inductor Ldc2 is connected to the negative electrode of the battery power source BAT via the battery relay RLY5. That is, in the preferred embodiment shown in FIG4 , the discharge device 300 includes four discharge switch tubes. In other words, in the preferred embodiment shown in FIG4 , the second discharge switch tube is composed of two switch tubes connected in series.

[0086] In the preferred embodiment shown in FIG4 , the first input terminal of the inverter device 200 is connected to the second terminal of the bus capacitor Cp and the first terminal of the bus capacitor Cn (ie, N IN The first terminal of the bus capacitor Cp is connected to the second terminal of the bus capacitor Cn, and the output terminal outputs the AC voltage.

[0087] Specifically, as shown in FIG4 , the inverter device 200 includes three inverter units corresponding to three-phase AC output. As shown in FIG4 , the first inverter unit includes switches Q11-Q14, diodes D11-D12, an inverter inductor Louta, and an inverter capacitor Couta. The second inverter unit includes switches Q15-Q18, diodes D21-D22, an inverter inductor Loutb, and an inverter capacitor Coutb. The third inverter unit includes switches Q19-Q22, diodes D31-D32, an inverter inductor Loutc, and an inverter capacitor Coutc. The control terminals of the switches Q11-Q22 receive corresponding control signals. The first terminals of the switches Q11, Q15, and Q19 are all connected to the first terminal of the bus capacitor Cp. The second terminals of the switches Q14, Q18, and Q22 are all connected to the second terminal of the bus capacitor Cn.

[0088] The second end of the switch tube Q11 is connected to the cathode of the diode D11 and the first end of the switch tube Q12, and the anode of the diode D11 is connected to the N IN The anode of diode D12 is connected to the second end of switch tube Q13 and the first end of switch tube Q14. The second end of switch tube Q12 is connected to the first end of switch tube Q13 and the first end of inverter inductor Louta. The second end of inverter inductor Louta is connected to N through inverter capacitor Couta. IN The second end of the switch tube Q14 is connected to the second end of the bus capacitor Cn. The second end of the switch tube Q15 is connected to the cathode of the diode D21 and the first end of the switch tube Q16, and the anode of the diode D21 is connected to N IN The anode of diode D22 is connected to the second end of switch tube Q17 and the first end of switch tube Q18. The second end of switch tube Q16 is connected to the first end of switch tube Q17 and the first end of inverter inductor Loutb. The second end of inverter inductor Loutb is connected to N through inverter capacitor Coutb. IN The second end of the switch tube Q18 is connected to the second end of the bus capacitor Cn. The second end of the switch tube Q19 is connected to the cathode of the diode D31 and the first end of the switch tube Q20, and the anode of the diode D31 is connected to N IN The anode of diode D32 is connected to the second end of switch tube Q21 and the first end of switch tube Q22. The second end of switch tube Q20 is connected to the first end of switch tube Q21 and the first end of inverter inductor Loutc. The second end of inverter inductor Loutc is connected to N through inverter capacitor Coutc. INThe second end of the switch tube Q22 is connected to the second end of the bus capacitor Cn. The second end of the inverter inductor Louta, the second end of the inverter inductor Loutb, and the second end of the inverter inductor Loutc respectively output three-phase AC voltages LA_out, LB_out, and LC_out.

[0089] The preferred embodiment shown in Figures 3-4 is applicable to three-phase AC input. The UPS rectification and discharge multiplexing converter of the present invention is also applicable to two-phase AC input. Figure 5 is a circuit diagram of another preferred embodiment of the UPS rectification and discharge multiplexing converter of the present invention, in which the inverter device is omitted, and it is applicable to two-phase input. The preferred embodiment shown in Figure 5 differs from the preferred embodiment shown in Figure 3 only in that its rectification device only includes two phases instead of three phases. Correspondingly, those skilled in the art know that its corresponding inverter device 200 only includes two inverter units, which will not be repeated here.

[0090] As shown in Figure 5, the rectifier device 100 includes a mains relay module consisting of mains relays RLYa and RLYb, a mains inductor module consisting of mains inductors La and Lb, a mains rectifier module consisting of diodes Da1, Da2, Db1, and Db2, a mains switch module consisting of switches Qa1, Qa2, Qb1, and Qb2, and a busbar module consisting of busbar capacitors Cp and Cn. Diodes Da1 and Da2 constitute a first rectifier unit, diodes Db1 and Db2 constitute a second rectifier unit, switches Qa1 and Qa2 constitute a first switch unit, and switches Qb1 and Qb2 constitute a second switch unit. The mains relay module, mains inductor module, mains rectifier module, and busbar module are connected in sequence; the mains switch module is simultaneously connected to the mains inductor module, mains rectifier module, and busbar module.

[0091] Furthermore, as shown in Figure 5, the first end of the AC relay RLYa is connected to the first AC input terminal LA_IN, the second end is connected to the first end of the AC inductor La, and the second end of the AC inductor La is connected to the anode of the diode Da1 and the cathode of the diode Da2 (i.e., the first end of the first rectifier unit) and the first end of the switch tube Qa1 (i.e., the first end of the first switch unit).

[0092] The first end of the AC relay RLYb is connected to the second AC input terminal LB_IN, and the second end is connected to the first end of the AC inductor Lb. The second end of the AC inductor Lb is connected to the anode of the diode Db1 and the cathode of the diode Db2 (i.e., the first end of the second rectifier unit) and the first end of the switch tube Qb1 (i.e., the first end of the second switch unit).

[0093] The cathode of the diode Da1 (i.e., the second end of the first rectifier unit) and the cathode of the diode Db1 (i.e., the second end of the second rectifier unit) are respectively connected to the first end of the bus capacitor Cp. The second end of the bus capacitor Cp is connected to the first end of the bus capacitor Cn. The anode of the diode Da2 (i.e., the third end of the first rectifier unit) and the anode of the diode Db2 (i.e., the third end of the second rectifier unit) are respectively connected to the second end of the bus capacitor Cn.

[0094] The second end of the switch transistor Qa2 (i.e., the second end of the first switch unit) and the second end of the switch transistor Qb2 (i.e., the second end of the second switch unit) are both connected to the second end of the bus capacitor Cp and the first end of the bus capacitor Cn. The control ends of the switches Qa1 and Qa2 (i.e., the control ends of the first switch unit) and the control ends of the switches Qb1 and Qb2 (i.e., the control ends of the second switch unit) receive corresponding control signals.

[0095] In this preferred embodiment, in mains mode, mains relays RLYa and RLYb, as well as battery relays RLY4 and RLY5, are closed, and multiplex relays RLY6 and RLY7 are opened. Switches Qa1, Qa2, Qb1, and Qb2 are PWM-modulated to charge bus capacitors Cp and Cn, respectively. Discharge switch transistors Q7 and Q9 are PWM-modulated to charge battery power source BAT. In battery mode, mains relays RLYa and RLYb are opened, battery relays RLY4 and RLY5, as well as multiplex relays RLY6 and RLY7, are closed. Discharge switch transistor Q8 is PWM-modulated to charge bus capacitors Cp and Cn, and switches Qa1, Qa2, Qb1, and Qb2 are PWM-modulated to charge bus capacitors Cp and Cn, respectively.

[0096] Figure 6 is a circuit diagram of another preferred embodiment of the UPS rectifier-discharge multiplexing converter of the present invention, in which the inverter device is omitted. The embodiment shown in Figure 6 differs from the embodiment shown in Figure 3 in that silicon-controlled rectifiers SCR1 and SCR2 are connected in parallel across multiplexing relays RLY6 and RLY7, respectively. Connecting silicon-controlled rectifiers in parallel across multiplexing relays RLY6 and RLY7 can reduce switching time and reduce busbar capacitance pressure.

[0097] The principles of each preferred embodiment of the present invention are similar. Since the present invention differs primarily from the prior art in the control process of the rectifier 100, discharger 300, and multiplexing device 400, while the operating principle and control process of the inverter 200 are identical to those of the prior art, to avoid obscuring the key points of the present invention with excessive irrelevant content, the present invention will primarily be described in detail below with reference to the circuit portion shown in FIG3 . FIG7A-H illustrate the current paths of the UPS rectifier-discharge multiplexing converter of the present invention in different modes.

[0098] The following description is made with reference to FIG. 3 and FIG. 7A-H .

[0099] As shown in Figure 3, the UPS rectifier-discharge multiplexing converter of the present invention includes switching transistors Qa1, Qa2, Qb1, Qb2, Qc1, and Qc2; discharge switching transistors Q7, Q8, and Q9; diodes Da1, Da2, Db1, Db2, Dc1, and Dc2; mains relays RLYa, RLYb, and RLYc; battery relays RLY4 and RLY5; multiplexing relays RLY6 and RLY7; mains inductors La, Lb, and Lc; battery inductors Ldc1 and Ldc2; bus capacitors Cp and Cn; and a battery power supply BAT. The battery power supply is preferably a two-wire battery. In this preferred embodiment, the switching transistor is preferably a triode.

[0100] As shown in Figure 3, mains relay RLYa, mains inductor La, and switching transistors Qa1 and Qa2 are connected in series; mains relay RLYb, mains inductor Lb, and switching transistors Qb1 and Qb2 are connected in series; and mains relay RLYc, mains inductor Lc, and switching transistors Qc1 and Qc2 are connected in series. In this preferred embodiment, the collectors of switching transistors Qa2, Qb2, and Qc2 converge at a point and are connected to the midpoint of bus capacitors Cp and Cn (i.e., terminal Nin). The anode of diode Da1 is connected to the right end of mains inductor La, and the cathode of diode Da1 is connected to bus capacitor Cp. The cathode of diode Da2 is connected to the right end of mains inductor La, and the anode of diode Da2 is connected to bus capacitor n. The anode of diode Db1 is connected to the right end of mains inductor Lb, and the cathode of diode Db1 is connected to bus capacitor p. The cathode of diode Db2 is connected to the right end of mains inductor Lb, and the anode of diode Db2 is connected to bus capacitor n. The anode of diode Dc1 is connected to the right end of the mains inductor Lc, and the cathode of diode Dc1 is connected to the bus capacitor p. The cathode of diode Dc2 is connected to the right end of the mains inductor Lc, and the anode of diode Dc2 is connected to the bus capacitor n.

[0101] Switches Q7, Q8, and Q9 are connected in series. The collector of switch Q7 is connected to bus capacitor Cp, and the emitter of switch Q9 is connected to bus capacitor Cn. The left end of battery inductor Ldc1 is connected to the emitter of switch Q7, and the right end is connected in series with battery relay RLY4. The left end of battery inductor Ldc2 is connected to the emitter of switch Q8, and the right end is connected in series with battery relay RLY5. Battery relay RLY4 is also connected to the positive terminal of the battery power supply, and battery relay RLY5 is also connected to the negative terminal of the battery power supply.

[0102] When the AC power is supplied, switches Qa1, Qa2, Qb1, Qb2, Qc1, and Qc2; diodes Da1, Da2, Db1, Db2, Dc1, and Dc2; AC relays RLYa, RLYb, and RLYc; and AC inductors La, Lb, and Lc operate to rectify AC to DC. Simultaneously, switches Q7, Q8, and Q9 and battery inductors Ldc1 and Ldc2 operate to convert the DC bus voltage to battery voltage.

[0103] In battery mode, switches Q7, Q8, and Q9, and battery inductors Ldc1 and Ldc2 operate in discharge mode. Meanwhile, AC relays RLYa, RLYb, and RLYc are disconnected, while multiplexer relays RLY6 and RLY7 are closed. Switches Qa1, Qa2, Qb1, and Qb2, diodes Da1, Da2, Db1, and Db2, and inductors La and Lb also operate in discharge mode.

[0104] In mains mode, mains relays RLYa, RLYb, and RLYc are closed, multiplexer relays RLY6 and RLY7 are open, and battery relays RLY4 and RLY5 are closed. In mains mode, phases A, B, and C operate in the same manner, so only phase A is used as an example. The principles for phases B and C are similar and will not be repeated here.

[0105] During the positive half-cycle of the mains, switches Qa1 and Qa2 perform PWM modulation. When switches Qa1 and Qa2 are on, the mains input current flows through mains relay RLYa, mains inductor La, switches Qa1 and Qa2. At this time, the inductor current in mains inductor La increases, as shown in Figure 7A. When switches Qa1 and Qa2 are off, the mains input current flows through mains relay RLYa, mains inductor La, diode Da1, and bus capacitor Cp. At this time, the inductor current in mains inductor La decreases, charging bus capacitor Cp, as shown in Figure 7B. During the negative half-cycle of the mains, switches Qa1 and Qa2 perform PWM modulation. When switches Qa1 and Qa2 are on, the mains input current flows through mains relay RLYa, mains inductor La, switches Qa1 and Qa2. At this time, the current in mains inductor La increases, as shown in Figure 7C. When switches Qa1 and Qa2 are off, the AC input current flows through AC relay RLYa, AC inductor La, diode Da2, and bus capacitor Cn. The inductive current in AC inductor La decreases, charging bus capacitor Cn, as shown in Figure 7D. The modulation of switches Qb1, Qb2, and Qc1, Qc2 for phases B and C is similar and will not be repeated here.

[0106] In AC power mode, switches Q7 and Q9 perform PWM modulation. When switches Q7 and Q9 are on, the charging current flows through switch Q7, battery inductor Ldc1, battery relay RLY4, battery power supply BAT, battery relay RLY5, battery inductor Ldc2, and switch Q9, causing the inductor currents in battery inductors Ldc1 and Ldc2 to increase. When switches Q7 and Q9 are off, the current flows through switch Q8, battery inductor Ldc1, battery relay RLY4, battery power supply BAT, battery relay RLY5, and battery inductor Ldc2, causing the inductor currents in battery inductors Ldc1 and Ldc2 to decrease.

[0107] In battery mode, the AC relays RLYa, RLYb, and RLYc are disconnected, the multiplexing relays RLY6 and RLY7 are closed, and the battery relays RLY4 and RLY5 are closed.

[0108] Switches Q7, Q8, Q9, battery inductor Ldc1, battery inductor Ldc2, battery relays RLY4, and battery relays RLY5 form discharge loop 1. Switch Q8 performs PWM modulation. When switch Q8 is on, current flows through switch Q8, battery inductor Ldc1, battery inductor Ldc2, battery relays RLY4, and battery relays RLY5, causing the inductor currents in battery inductors Ldc1 and Ldc2 to increase, as shown in Figure 7E . When switch Q8 is closed, current flows through bus capacitors Cp and Cn, switch Q7, Q9, battery inductor Ldc1, battery inductor Ldc2, battery relays RLY4, and battery relays RLY5, causing the inductor currents in battery inductors Ldc1 and Ldc2 to decrease, charging bus capacitors Cp and Cn, as shown in Figure 7F .

[0109] At the same time, multiplexing relay RLY6, mains inductor La, switches Qa1, Qa2, diode Da1, Qb1, Qb2, mains inductor Lb, diode Db2, and multiplexing relay RLY7 form discharge loop 2. Switches Qa1, Qa2, Qb1, and Qb2 perform PWM modulation. When switches Qa1, Qa2, Qb1, and Qb2 are turned on, current flows through multiplexing relay RLY6, mains inductor La, switches Qa1, Qa2, Qb1, Qb2, mains inductor Lb, and multiplexing relay RLY7, causing the inductor currents in mains inductors La and Lb to increase, as shown in Figure 7G. When the switches Qa1, Qa2, Qb1, and Qb2 are turned off, current flows through the multiplexing relay RLY6, the mains inductor La, the diode Da1, the bus capacitor Cp, the bus capacitor Cn, the diode Db2, the mains inductor Lb, and the multiplexing relay RLY7. The inductive currents of the mains inductors La and Lb decrease, and the currents charge the bus capacitors Cp and Cn, as shown in FIG7H .

[0110] Therefore, the present invention multiplexes the rectifier device in time-sharing mode, that is, in battery mode, the rectifier device is multiplexed by the multiplexing device to serve as an auxiliary discharge device to receive the battery voltage and provide the battery voltage to the inverter device. In battery mode, the rectifier device can be multiplexed as an auxiliary discharge device to share the discharge power of the independent discharge device. Compared with the traditional uninterruptible power supply converter, the present invention can reduce the design power level of the independent discharge device, reduce the design pressure of the discharge device, improve the utilization rate of the device, and reduce the cost and volume of the UPS rectifier-discharge multiplexing converter.

[0111] Furthermore, the switching control sequence of the mains power supply and battery power supply of the UPS rectification and discharge multiplexing converter of the present invention is shown in FIG8 .

[0112] Assuming that before time t1, the system is in mains power mode, switches Qa1, Qa2, Qb1, Qb2, Qc1, and Qc2 are PWM-modulated. Switches Q7 and Q9 are turned off, mains relays RLYa, RLYb, and RLYc are closed, and multiplex relays RLY6 and RLY7 are opened. At time t1, the mains power mode switches to battery power mode. A first drive signal is sent to mains relays RLYa, RLYb, and RLYc to shut them off. Because relay contacts operate slower than the drive signal, at time t1, the contacts of mains relays RLYa, RLYb, and RLYc remain closed. At time t2, the contacts of mains relays RLYa, RLYb, and RLYc open, and a second drive signal is sent to relays RLY6 and RLY7 to close the multiplex relays. Similarly, the contacts of multiplex relays RLY6 and RLY7 remain open. At time t3, the contacts of multiplexing relays RLY6 and RLY7 close. A short time later, at time t4, switches Q1 and Q2 start PWM modulation in battery power mode, and the UPS rectifier-discharge multiplexing converter switches to battery power mode.

[0113] Assume that at time t5, the switch from battery mode to mains mode begins. At this time, switches Q7 and Q10 are turned off, and a third drive signal is sent to multiplexing relays RLY6 and RLY7 to drive them off. Similarly, the contacts of multiplexing relays RLY6 and RLY7 remain closed. At time t6, the contacts of multiplexing relays RLY6 and RLY7 open. At this time, a fourth drive signal is sent to mains relays RLYa, RLYb, and RLYc to close them. At time t7, the contacts of mains relays RLYa, RLYb, and RLYc close. A short time later, at time t8, switches Qa1, Qa2, Qb1, Qb2, Qc1, and Qc2 perform PWM modulation in mains mode. Switches Q7 and Q9 are turned off, and the rectifier converter switches to mains mode.

[0114] Through the above-mentioned timing control, the UPS rectification and discharge multiplexing converter can be smoothly switched from battery mode to mains mode, and from mains mode to battery mode.

[0115] The present invention further provides a control method for the three-phase UPS rectifier-discharge multiplexing converter shown in Figures 3-4. As described above, the UPS rectifier-discharge multiplexing converter includes a rectifier, a discharger, an inverter, and a multiplexing device; the rectifier includes a first mains relay, a second mains relay, a third mains relay, a first rectifier unit, a second rectifier unit, a third rectifier unit, a first switch unit, a second switch unit, a third switch unit, a first bus capacitor, and a second bus capacitor; the multiplexing device includes a first multiplexing relay and a second multiplexing relay; and the discharge device includes a first discharge switching tube, a second discharge switching tube, a third discharge switching tube, a first battery relay, and a second battery relay. The control method of the UPS rectifier-discharge multiplexing converter includes: in a mains mode, closing the first mains relay, the second mains relay, and the third mains relay, as well as the first battery relay and the second battery relay, disconnecting the first multiplexing relay and the second multiplexing relay, performing PWM modulation on the first switch unit, the second switch unit, and the third switch unit respectively to charge the first bus capacitor and the second bus capacitor, and performing PWM modulation on the first discharge switch tube and the third discharge switch tube respectively to charge the battery power supply; in a battery mode, disconnecting the first mains relay, the second mains relay, and the third mains relay, closing the first battery relay and the second battery relay, as well as the first multiplexing relay and the second multiplexing relay, performing PWM modulation on the second discharge switch tube to charge the first bus capacitor and the second bus capacitor, and performing PWM modulation on the first switch unit and the second switch unit respectively to charge the first bus capacitor and the second bus capacitor.

[0116] Preferably, the method further includes, when switching from the AC power mode to the battery mode, sending a first drive signal at a first moment to drive the AC power relay to close, and the contacts of the AC power relay are disconnected at a second moment; sending a second drive signal at the second moment to drive the multiplexing relay to close, and the multiplexing relay is closed at a third moment; at a fourth moment, the switching unit performs PWM modulation under battery mode, and the switching is completed; wherein the fourth moment is later than the third moment, the third moment is later than the second moment, and the second moment is later than the first moment.

[0117] Preferably, the method further includes, when switching from the battery mode to the AC power mode, sending a third drive signal at the fifth moment to drive the multiplexing relay to close, and the contacts of the multiplexing relay are disconnected at the sixth moment; sending a fourth drive signal at the sixth moment to drive the AC power relay to close, and the AC power relay is closed at the seventh moment; at the eighth moment, the switching unit performs PWM modulation under the AC power mode, and the switching is completed; wherein the eighth moment is later than the seventh moment, the seventh moment is later than the sixth moment, and the sixth moment is later than the fifth moment.

[0118] The present invention further provides a control method for the two-phase UPS rectifier-discharge multiplexing converter shown in Figure 5. As previously described, the UPS rectifier-discharge multiplexing converter includes a rectifier, a discharger, an inverter, and a multiplexing device; the rectifier includes a first mains relay, a second mains relay, a first rectifier unit, a second rectifier unit, a first switch unit, a second switch unit, a first bus capacitor, and a second bus capacitor; the multiplexing device includes a first multiplexing relay and a second multiplexing relay; the discharge device includes a first discharge switching tube, a second discharge switching tube, a third discharge switching tube, a first battery relay, and a second battery relay;

[0119] The control method of the UPS rectifier-discharge multiplexing converter includes: in mains mode, closing the first mains relay and the second mains relay as well as the first battery relay and the second battery relay, disconnecting the first multiplexing relay and the second multiplexing relay, performing PWM modulation on the first switch unit and the second switch unit respectively to charge the first bus capacitor and the second bus capacitor, and performing PWM modulation on the first discharge switch tube and the third discharge switch tube respectively to charge the battery power supply; in battery mode, disconnecting the first mains relay and the second mains relay, closing the first battery relay and the second battery relay as well as the first multiplexing relay and the second multiplexing relay, performing PWM modulation on the second discharge switch tube to charge the first bus capacitor and the second bus capacitor, and performing PWM modulation on the first switch unit and the second switch unit respectively to charge the first bus capacitor and the second bus capacitor.

[0120] Preferably, the method further includes, when switching from the AC power mode to the battery mode, sending a first drive signal at a first moment to drive the AC power relay to close, and the contacts of the AC power relay are disconnected at a second moment; sending a second drive signal at the second moment to drive the multiplexing relay to close, and the multiplexing relay is closed at a third moment; at a fourth moment, the switching unit performs PWM modulation under battery mode, and the switching is completed; wherein the fourth moment is later than the third moment, the third moment is later than the second moment, and the second moment is later than the first moment.

[0121] Preferably, the method further includes, when switching from the battery mode to the AC power mode, sending a third drive signal at the fifth moment to drive the multiplexing relay to close, and the contacts of the multiplexing relay are disconnected at the sixth moment; sending a fourth drive signal at the sixth moment to drive the AC power relay to close, and the AC power relay is closed at the seventh moment; at the eighth moment, the switching unit performs PWM modulation under the AC power mode, and the switching is completed; wherein the eighth moment is later than the seventh moment, the seventh moment is later than the sixth moment, and the sixth moment is later than the fifth moment.

[0122] For further description of the control method of the three-phase UPS rectification and discharge multiplexing converter of the present invention, reference can be made to the embodiments shown in Figures 3-8, which will not be repeated here.

[0123] The present invention multiplexes the rectifier device in time-sharing mode, that is, in battery mode, the rectifier device is multiplexed by the multiplexing device to serve as an auxiliary discharge device to receive the battery voltage and provide the battery voltage to the inverter device. In battery mode, the rectifier device can be multiplexed as an auxiliary discharge device to share the discharge power of the independent discharge device. Compared with the traditional uninterruptible power supply converter, the present invention can reduce the design power level of the independent discharge device, reduce the design pressure of the discharge device, improve the utilization rate of the device, and reduce the cost and volume of the UPS rectifier-discharge multiplexing converter.

[0124] Although the present invention is described by way of specific embodiments, it will be understood by those skilled in the art that various modifications and equivalent substitutions may be made to the present invention without departing from the scope of the present invention. Furthermore, various modifications may be made to the present invention for specific circumstances or materials without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed, but is intended to encompass all embodiments falling within the scope of the claims.

[0125] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A UPS rectifier-discharge multiplexing converter, comprising a rectifier connected to a mains supply, a discharger connected to a battery power supply, and an inverter connected to both the rectifier and the discharger, characterized in that: further comprising a multiplexing device connected between the battery power source and the rectifying device; In the mains mode, the rectifier is used to convert the mains into a DC voltage and provide it to the inverter and the battery power supply respectively. The inverter receives the DC voltage and converts it into an AC voltage for output; In battery mode, the discharge device is used to receive the battery voltage and provide the battery voltage to the inverter device, while the multiplexing device multiplexes the rectifier device to serve as an auxiliary discharge device to receive the battery voltage and provide the battery voltage to the inverter device, and the inverter device receives the battery voltage from the discharge device and the rectifier device respectively and converts them into AC voltage output.

2. The UPS rectification and discharge multiplexing converter according to claim 1, characterized in that: The rectifier device includes a mains relay module, a mains inductor module, a mains rectifier module, a mains switch module and a bus module; The mains relay module, the mains inductor module, the mains rectifier module and the bus module are connected in sequence; the mains switch module is connected to the mains inductor module, the mains rectifier module and the bus module at the same time.

3. The UPS rectification and discharge multiplexing converter according to claim 2, characterized in that: The mains relay module includes a first mains relay, a second mains relay and a third mains relay; The AC inductor module includes a first AC inductor, a second AC inductor and a third AC inductor; The mains rectifier module comprises a first rectifier unit, a second rectifier unit and a third rectifier unit; The mains switch module comprises a first switch unit, a second switch unit and a third switch unit; The bus module includes a first bus capacitor and a second bus capacitor; The first end of the first AC relay is connected to the first AC input end, the second end is connected to the first end of the first AC inductor, and the second end of the first AC inductor is connected to the first end of the first rectifier unit and the first end of the first switch unit; The first end of the second AC relay is connected to the second AC input terminal, and the second end is connected to the second a first end of a mains inductor, and a second end of the second mains inductor connected to a first end of the second rectifier unit and a first end of the second switch unit; The first end of the third AC relay is connected to the third AC input end, the second end is connected to the first end of the third AC inductor, and the second end of the third AC inductor is connected to the first end of the third rectifier unit and the first end of the third switch unit; The second end of the first rectifier unit, the second end of the second rectifier unit, and the second end of the third rectifier unit are respectively connected to the first end of the first bus capacitor, the second end of the first bus capacitor is connected to the first end of the second bus capacitor, and the third end of the first rectifier unit, the third end of the second rectifier unit, and the third end of the third rectifier unit are respectively connected to the second end of the second bus capacitor; The second end of the first switch unit, the second end of the second switch unit and the second end of the third switch unit are all connected to the second end of the first bus capacitor and the first end of the second bus capacitor, and the control end of the first switch unit, the control end of the second switch unit and the control end of the third switch unit respectively receive corresponding control signals.

4. The UPS rectification and discharge multiplexing converter according to claim 2, characterized in that: The mains relay module comprises a first mains relay and a second mains relay; The mains inductor module includes a first mains inductor and a second mains inductor; The mains rectifier module comprises a first rectifier unit and a second rectifier unit; The mains switch module comprises a first switch unit and a second switch unit; The bus module includes a first bus capacitor and a second bus capacitor; The first end of the first AC relay is connected to the first AC input end, the second end is connected to the first end of the first AC inductor, and the second end of the first AC inductor is connected to the first end of the first rectifier unit and the first end of the first switch unit; The first end of the second AC relay is connected to the second AC input end, the second end is connected to the first end of the second AC inductor, and the second end of the second AC inductor is connected to the first end of the second rectifier unit and the first end of the second switch unit; The second end of the first rectifier unit and the second end of the second rectifier unit are respectively connected to the first end of the first bus capacitor, the second end of the first bus capacitor is connected to the first end of the second bus capacitor, and the third end of the first rectifier unit and the third end of the second rectifier unit are respectively connected to the a second terminal of the second bus capacitor; The second end of the first switch unit and the second end of the second switch unit are both connected to the second end of the first bus capacitor and the first end of the second bus capacitor, and the control end of the first switch unit and the control end of the second switch unit receive corresponding control signals respectively.

5. The UPS rectification and discharge multiplexing converter according to claim 3 or 4, characterized in that: The rectifier unit includes a first diode and a second diode, wherein the anode of the first diode is connected to the cathode of the second diode and serves as the first end of the rectifier unit, the cathode of the first diode serves as the second end of the rectifier unit, and the anode of the second diode serves as the third end of the rectifier unit.

6. The UPS rectification and discharge multiplexing converter according to claim 3 or 4, characterized in that: The switch unit includes a first switch tube and a second switch tube, the control ends of the first switch tube and the second switch tube serve as the control end of the switch unit, the first end of the first switch tube serves as the first end of the switch unit, the second end of the first switch tube is connected to the first end of the second switch tube, and the second end of the second switch tube serves as the second end of the switch unit.

7. The UPS rectification and discharge multiplexing converter according to claim 3 or 4, characterized in that: The multiplexing device includes a first multiplexing relay and a second multiplexing relay, wherein the first end of the first multiplexing relay is connected to the second end of the first AC power relay, and the second end is connected to the positive pole of the battery power supply, and the first end of the second multiplexing relay is connected to the second end of the second AC power relay, and the second end is connected to the negative pole of the battery power supply.

8. The UPS rectification and discharge multiplexing converter according to claim 7, characterized in that: Two ends of the first multiplex relay and the second multiplex relay are respectively connected in parallel with a silicon controlled rectifier.

9. The UPS rectification and discharge multiplexing converter according to claim 3 or 4, characterized in that: The discharge device includes a first discharge switch tube, a second discharge switch tube, a third discharge switch tube, a first battery inductor, a second battery inductor, a first battery relay and a second battery relay; The control ends of the first discharge switch tube, the second discharge switch tube and the third discharge switch tube receive corresponding control signals respectively. The first end of the first discharge switch tube is connected to the first end of the first bus capacitor, and the second end is connected to the first end of the first battery inductor and the first end of the second discharge switch tube. The second end of the second discharge switch tube is connected to the first end of the third discharge switch tube and the first end of the second battery inductor. The second end of the third discharge switch tube is connected to the second end of the second bus capacitor. The second end of the first battery inductor is connected to the battery inductor via the first battery relay. The second end of the second battery inductor is connected to the positive electrode of the battery power source, and the second end of the second battery inductor is connected to the negative electrode of the battery power source via the second battery relay.

10. The UPS rectification and discharge multiplexing converter according to claim 3 or 4, characterized in that: The first input end of the inverter device is connected to the second end of the first bus capacitor and the first end of the second bus capacitor, the second input end is connected to the first end of the first bus capacitor, the third input end is connected to the second end of the second bus capacitor, and the output end outputs the AC voltage.

11. A control method for a UPS rectifier-discharge multiplexing converter, characterized in that: The UPS rectification and discharge multiplexing converter comprises a rectification device, a discharge device, an inverter device and a multiplexing device; the rectification device comprises a first AC relay, a second AC relay, a first rectification unit, a second rectification unit, a first switch unit, a second switch unit, a first bus capacitor and a second bus capacitor; the multiplexing device comprises a first multiplexing relay and a second multiplexing relay; the discharge device comprises a first discharge switch tube, a second discharge switch tube, a third discharge switch tube, a first battery relay and a second battery relay; The control method of the UPS rectification and discharge multiplexing converter comprises: In the mains mode, the first mains relay and the second mains relay as well as the first battery relay and the second battery relay are closed, the first multiplexing relay and the second multiplexing relay are opened, the first switch unit and the second switch unit are PWM modulated respectively, so as to charge the first bus capacitor and the second bus capacitor, and the first discharge switch tube and the third discharge switch tube are PWM modulated respectively, so as to charge the battery power supply; In battery mode, the first AC power relay and the second AC power relay are disconnected, the first battery relay and the second battery relay as well as the first multiplex relay and the second multiplex relay are closed, the second discharge switch tube is PWM modulated to charge the first bus capacitor and the second bus capacitor, and the first switch unit and the second switch unit are PWM modulated respectively to charge the first bus capacitor and the second bus capacitor.

12. A control method for a UPS rectifier-discharge multiplexing converter, characterized in that: The UPS rectifying and discharging multiplexing converter comprises a rectifying device, a discharging device, an inverting device and a multiplexing device; the rectifying device comprises a first AC relay, a second AC relay, a third AC relay, a first rectifying unit, a second rectifying unit, a third rectifying unit, a first switch unit, a second switch unit, a third switch unit, a first bus capacitor and a second bus capacitor; the multiplexing device comprises a first multiplexing relay and a second multiplexing relay; the discharging device comprises a first discharging switch tube, a second discharging switch tube, a third discharging switch tube, a first battery relay and a second battery relay; The control method of the UPS rectification and discharge multiplexing converter comprises: In the mains mode, the first mains relay, the second mains relay and the third mains relay as well as the first battery relay and the second battery relay are closed, the first multiplexing relay and the second multiplexing relay are disconnected, the first switch unit, the second switch unit and the third switch unit are PWM modulated respectively, so as to charge the first bus capacitor and the second bus capacitor, and the first discharge switch tube and the third discharge switch tube are PWM modulated respectively, so as to charge the battery power supply; In battery mode, the first AC power relay, the second AC power relay and the third AC power relay are disconnected, the first battery relay and the second battery relay as well as the first multiplex relay and the second multiplex relay are closed, the second discharge switch tube is PWM modulated to charge the first bus capacitor and the second bus capacitor, and the first switch unit and the second switch unit are PWM modulated respectively to charge the first bus capacitor and the second bus capacitor.

13. The control method of the UPS rectification and discharge multiplexing converter according to claim 11 or 12, characterized in that: Further including: When switching from the AC power mode to the battery mode, a first drive signal is sent at a first moment to drive the AC power relay to close, and the contact of the AC power relay is disconnected at a second moment; Sending a second driving signal at the second moment to drive the multiplexing relay to close, and the multiplexing relay to close at a third moment; At the fourth moment, the switch unit performs PWM modulation in the battery mode, and the switching is completed; The fourth moment is later than the third moment, the third moment is later than the second moment, and the second moment is later than the first moment.

14. The control method of the UPS rectification and discharge multiplexing converter according to claim 11 or 12, characterized in that: Further including: When switching from the battery mode to the mains mode, sending a third drive signal at a fifth moment to drive the multiplexing relay to close, and the contact of the multiplexing relay is disconnected at a sixth moment; Sending a fourth drive signal at the sixth moment to drive the AC power relay to close, and the AC power relay closes at the seventh moment; At the eighth moment, the switch unit performs PWM modulation in the mains mode, and the switching is completed; The eighth moment is later than the seventh moment, the seventh moment is later than the sixth moment, and the sixth moment is later than the fifth moment.

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