Rectifying circuit and control method thereof

Abstract

The invention discloses a rectifying circuit and a control method thereof. The rectifying circuit comprises six first switch modules, six second switch modules and six bridge arm units; the first bridge arm unit and the second bridge arm unit are respectively connected with a first phase of alternating current through two first switch modules, and the third bridge arm unit and the fourth bridge arm unit are respectively connected with a second phase of the alternating current through two first switch modules. The fifth bridge arm unit and the sixth bridge arm unit are respectively connected with the second phase of the alternating current through two first switch modules; the first bridge arm unit, the second bridge arm unit and the third bridge arm unit are respectively connected with the first pole of the battery through three second switch modules; and the fourth bridge arm unit, the fifth bridge arm unit and the sixth bridge arm unit are respectively connected with the second pole of the battery through three second switch modules. According to the invention, the ripple current input by the commercial power and the ripple current input by the battery can be reduced, and the circuit utilization rate is improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of circuit technology, and in particular to a rectifier circuit and a control method thereof. Background Art

[0002] At present, the three-phase Vienna Power Factor Correction (PFC) circuit is widely used in the rectifier circuit part of the Uninterruptible Power System (UPS) due to its advantages such as high conversion efficiency.

[0003] Figure 1 The invention discloses an existing Vienna rectifier circuit, which mainly comprises: a three-phase AC power supply (mains power) A phase 101, B phase 102 and C phase 103, a positive battery electrode BAT+ and a negative battery electrode BAT-, selection switches A1, A2 and A3, inductors L1, L2 and L3, diodes D1, D2, D3, D4, D5 and D6, switch tubes Q1, Q2 and Q3, capacitors C1 and C2 and a neutral line N, wherein A1 can be selected to be connected to phase A or BAT+, A2 can be selected to be connected to phase B or not, and A3 can be selected to be connected to phase C or BAT-. The mains power and the battery are switched through a relay, and each phase in the three-phase circuit has the same working principle in the mains power mode, and phases A and C work in the battery mode, while phase B does not work. In this circuit, the mains power and the battery share a boost circuit (boost circuit) part, but since the phase B circuit is not used, the circuit utilization rate is not high in the battery mode, and is affected by the capacitor ripple. Summary of the invention

[0004] The present invention provides a rectifier circuit and a control method thereof, so as to improve the circuit utilization rate and reduce the ripple current of the battery input.

[0005] In a first aspect, an embodiment of the present invention provides a rectifier circuit, the rectifier circuit comprising six first switch modules, six second switch modules and six bridge arm units, the six bridge arm units are respectively a first bridge arm unit, a second bridge arm unit, a third bridge arm unit, a fourth bridge arm unit, a fifth bridge arm unit and a sixth bridge arm unit;

[0006] The first bridge arm unit and the second bridge arm unit are connected to the first phase of the alternating current through two of the first switch modules respectively, the third bridge arm unit and the fourth bridge arm unit are connected to the second phase of the alternating current through two of the first switch modules respectively, and the fifth bridge arm unit and the sixth bridge arm unit are connected to the third phase of the alternating current through two of the first switch modules respectively;

[0007] The first bridge arm unit, the second bridge arm unit and the third bridge arm unit are connected to the first pole of the battery through three second switch modules respectively, and the fourth bridge arm unit, the fifth bridge arm unit and the sixth bridge arm unit are connected to the second pole of the battery through three second switch modules respectively.

[0008] Furthermore, the rectifier circuit also includes a first capacitor and a second capacitor;

[0009] Each of the bridge arm units includes two diodes, an inductor and a combination switch, the two diodes are respectively a first diode and a second diode, the input end of the first diode is connected to the output end of the second diode, the connection between the first diode and the second diode is respectively connected to the first port of the inductor and the first port of the combination switch, and the second port of the combination switch is connected to the neutral line; the output end of the first diode is connected to the first port of the first capacitor, the input end of the second diode is connected to the first port of the second capacitor, and the second port of the first capacitor is connected to the second port of the second capacitor and the neutral line.

[0010] Furthermore, the combined switch includes two switch tubes connected in series.

[0011] Furthermore, the combined switch includes a switch tube, a third diode, a fourth diode, a fifth diode and a sixth diode;

[0012] The first end of the third diode is connected to the second end of the third diode, and the connection point between the third diode and the third diode serves as the first port of the combination switch; the second end of the third diode and the fifth diode are connected to the second end of the switch tube, the second end of the third diode and the fifth diode are connected to the third end of the switch tube, and the first end of the switch tube is the control end; the first end of the fifth diode is connected to the second end of the fifth diode, and the connection point between the fifth diode and the fifth diode serves as the first port of the combination switch. Furthermore, the rectifier circuit also includes a control unit, which is connected to each of the combination switches;

[0013] The control unit is used to send a control signal to each of the combination switches to control the on and off of each of the combination switches.

[0014] In a second aspect, an embodiment of the present invention further provides a control method for a rectifier circuit, wherein the control method for a rectifier circuit is used to control the rectifier circuit described in any embodiment of the present invention, and includes:

[0015] In the mains working mode, the first bridge arm unit and the second bridge arm unit are controlled to be connected to the first phase of the alternating current, the third bridge arm unit and the fourth bridge arm unit are controlled to be connected to the second phase of the alternating current, and the fifth bridge arm unit and the sixth bridge arm unit are controlled to be connected to the third phase of the alternating current;

[0016] In the battery working mode, the first bridge arm unit and the second bridge arm unit are controlled to be connected to the first pole of the battery, the third bridge arm unit is controlled to be connected to the first pole of the battery, the fourth bridge arm unit is controlled to be connected to the second pole of the battery, and the fifth bridge arm unit and the sixth bridge arm unit are controlled to be connected to the second pole of the battery.

[0017] Furthermore, the method further comprises: in the mains operation mode, sending PWM control signals corresponding to each of the combination switches respectively;

[0018] Wherein, in the AC power working mode, the carrier signal corresponding to the combination switch of the first bridge arm unit and the carrier signal corresponding to the combination switch of the second bridge arm unit are out of phase by 180 degrees, the carrier signal corresponding to the combination switch of the third bridge arm unit and the carrier signal corresponding to the combination switch of the fourth bridge arm unit are out of phase by 180 degrees, and the carrier signal corresponding to the combination switch of the fifth bridge arm unit and the carrier signal corresponding to the combination switch of the sixth bridge arm unit are out of phase by 180 degrees; and the carrier signal corresponding to the combination switch of the first bridge arm unit, the carrier signal corresponding to the combination switch of the third bridge arm unit and the carrier signal corresponding to the combination switch of the fifth bridge arm unit are out of phase by 120 degrees, and the carrier signal corresponding to the combination switch of the second bridge arm unit, the carrier signal corresponding to the combination switch of the fourth bridge arm unit and the carrier signal corresponding to the combination switch of the sixth bridge arm unit are out of phase by 120 degrees.

[0019] Furthermore, the method further comprises: in the battery operation mode, sending PWM control signals corresponding to each of the combination switches respectively;

[0020] Wherein, in the battery working mode, the carrier signal corresponding to the combination switch of the first bridge arm unit is synchronized with the carrier signal corresponding to the combination switch of the fourth bridge arm unit, the carrier signal corresponding to the combination switch of the second bridge arm unit is synchronized with the carrier signal corresponding to the combination switch of the fifth bridge arm unit, and the carrier signal corresponding to the combination switch of the third bridge arm unit is synchronized with the carrier signal corresponding to the combination switch of the sixth bridge arm unit; and the carrier signal corresponding to the combination switch of the first bridge arm unit, the carrier signal corresponding to the combination switch of the second bridge arm unit, and the carrier signal corresponding to the combination switch of the third bridge arm unit are out of phase by 120 degrees, and the carrier signal corresponding to the combination switch of the fourth bridge arm unit, the carrier signal corresponding to the combination switch of the fifth bridge arm unit, and the carrier signal corresponding to the combination switch of the sixth bridge arm unit are out of phase by 120 degrees.

[0021] Furthermore, the method further comprises:

[0022] When the AC working mode is switched to the battery working mode, the driving of the combination switches in each of the bridge arm units is first turned off, and the sending of the PWM control signals corresponding to each of the combination switches in the AC working mode is stopped; after a first time, the connection between each phase of the AC power and the bridge arm unit is disconnected, and the AC working mode is exited; after a second time, the connection between the two poles of the battery and the bridge arm unit is established; after a third time, the driving of each of the combination switches is turned on, and the PWM control signals corresponding to each of the combination switches in the battery working mode are sent, and the battery working mode is entered.

[0023] Furthermore, the method further comprises:

[0024] When the battery working mode is switched to the AC power working mode, firstly, the driving of the combination switches in each of the bridge arm units is turned off, and the sending of the PWM control signals corresponding to each of the combination switches in the battery working mode is stopped; after a fourth time, the connection between the two poles of the battery and the bridge arm unit is disconnected, and the battery working mode is exited; after a fifth time, the connection between each phase of the alternating current and the bridge arm unit is established; after a sixth time, the driving of each of the combination switches is turned on, and the PWM control signals corresponding to each of the combination switches in the AC power working mode are sent, and the AC power working mode is entered.

[0025] The present invention provides a rectifier circuit and a control method thereof. The rectifier circuit includes six first switch modules, six second switch modules and six bridge arm units. The six bridge arm units are respectively a first bridge arm unit, a second bridge arm unit, a third bridge arm unit, a fourth bridge arm unit, a fifth bridge arm unit and a sixth bridge arm unit; the first bridge arm unit and the second bridge arm unit are respectively connected to the first phase of the alternating current through two first switch modules, the third bridge arm unit and the fourth bridge arm unit are respectively connected to the second phase of the alternating current through two first switch modules, and the fifth bridge arm unit and the sixth bridge arm unit are respectively connected to the second phase of the alternating current through two first switch modules; the first bridge arm unit, the second bridge arm unit and the third bridge arm unit are respectively connected to the first pole of the battery through three second switch modules, and the fourth bridge arm unit, the fifth bridge arm unit and the sixth bridge arm unit are respectively connected to the second pole of the battery through three second switch modules. By separating the first pole of the battery and the second pole of the battery in the entire main power circuit, crossing is avoided. In this way, when designing a circuit board, the distance between the first pole of the battery and the second pole of the battery can be designed to be very large, which can greatly reduce the risk of battery arcing and fire. The present invention can realize that when the circuit is in the AC working mode and the battery working mode, different bridge arm units can be controlled to be independently turned on, so that the conduction time of different bridge arm units is out of phase, thereby reducing the ripple current of the AC input and the ripple current of the battery input. In addition, since there are no idle devices in the circuit when the circuit is in the battery working mode, the circuit utilization rate is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is an existing Vienna rectifier circuit.

[0027] Figure 2 A circuit diagram of a rectifier circuit provided by an embodiment of the present invention.

[0028] Figure 3 A schematic diagram of the structure of a combination switch provided in an embodiment of the present invention.

[0029] Figure 4 A schematic diagram of the structure of another combination switch provided by an embodiment of the present invention.

[0030] Figure 5 A schematic diagram of the structure of another combination switch provided by an embodiment of the present invention.

[0031] Figure 6 A control principle diagram of a control unit provided in an embodiment of the present invention.

[0032] Figure 7 A schematic diagram of waveforms of control signals of various combination switches in a mains power working mode provided by an embodiment of the present invention.

[0033] Figure 8A schematic diagram of waveforms of control signals of various combination switches in a battery working mode provided by an embodiment of the present invention.

[0034] Fig. 9 A timing diagram of switching from a mains operating mode to a battery operating mode provided in an embodiment of the present invention.

[0035] Fig.10 A timing diagram of switching from a battery operating mode to a mains operating mode provided in an embodiment of the present invention.

[0036] Fig.11 The present invention provides a flow chart of a control method for a rectifier circuit. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0038] In order to solve the technical problem of low circuit utilization in the prior art and reduce the ripple current of the mains input and the ripple current of the battery input, an embodiment of the present invention provides a rectifier circuit. Figure 2 A circuit diagram of a rectifier circuit provided by an embodiment of the present invention is shown in FIG. Figure 2 As shown, the rectifier circuit includes six first switch modules 301, six second switch modules 302 and six bridge arm units, and the six bridge arm units are respectively the first bridge arm unit M1, the second bridge arm unit M2, the third bridge arm unit M3, the fourth bridge arm unit M4, the fifth bridge arm unit M5 and the sixth bridge arm unit M6; the first bridge arm unit M1 and the second bridge arm unit M2 are respectively connected to the first phase 201 of the alternating current through two first switch modules 301, the third bridge arm unit M3 and the fourth bridge arm unit M4 are respectively connected to the second phase 202 of the alternating current through two first switch modules 301, and the fifth bridge arm unit M5 and the sixth bridge arm unit M6 are respectively connected to the third phase 203 of the alternating current through two first switch modules 301; the first bridge arm unit M1, the second bridge arm unit M2 and the third bridge arm unit M3 are respectively connected to the first pole of the battery through three second switch modules 302, and the fourth bridge arm unit M4, the fifth bridge arm unit M5 and the sixth bridge arm unit M6 are respectively connected to the second pole of the battery through three second switch modules 302.

[0039] The alternating current is the mains, and the battery is a direct current battery. The rectifier circuit of the embodiment of the present invention has a total of 6 bridge arm units, each phase of the mains is connected to two bridge arm units, and the circuit structure of each bridge arm unit is consistent. Each bridge arm unit can be connected to each phase of the alternating current and the two poles of the battery through the first switch module 301 and the second switch module 302.

[0040] Specifically, the first phase 201 of the alternating current is connected to the first bridge arm unit M1 and the second bridge arm unit M2, the second phase 202 of the alternating current is connected to the third bridge arm unit M3 and the fourth bridge arm unit M4, the third phase 203 of the alternating current is connected to the fifth bridge arm unit M5 and the sixth bridge arm unit M6, and the first electrode of the battery (such as Figure 2 As shown, the first pole can be the positive pole of the battery BAT+) connecting the first bridge arm unit M1, the second bridge arm unit M2 and the third bridge arm unit M3, and the second pole of the battery (such as Figure 2 As shown, the second pole may be the negative pole of the battery (BAT-) connected to the fourth bridge arm unit M4, the fifth bridge arm unit M5 and the sixth bridge arm unit M6. In the embodiment of the present invention, the first pole of the battery is connected to the first bridge arm unit M1, the second bridge arm unit M2 and the third bridge arm unit M3, and the second pole of the battery is connected to the fourth bridge arm unit M4, the fifth bridge arm unit M5 and the sixth bridge arm unit M6 for the following purpose: in the high-power UPS market application with ultra-high power density, since the battery is a DC voltage with no zero-crossing voltage, it is difficult to extinguish the arc after the battery arcs, and the battery arcing becomes one of the main causes of UPS fires. Figure 2 As shown, the embodiment of the present invention separates the positive electrode of the battery and the negative electrode of the battery in the entire main power circuit, and the circuit of the bridge arm unit connected to the positive electrode of the battery and the negative electrode of the battery can be divided into two independent areas to avoid crossing. In this way, when designing the circuit board, the distance between the positive electrode of the battery and the negative electrode of the battery can be designed to be large, which can greatly reduce the risk of battery arcing and fire. In addition, the rectifier circuit can control the independent conduction of different bridge arm units in the AC working mode and the battery working mode, so that the conduction time of different bridge arm units is out of phase, thereby reducing the ripple current of the AC input and the ripple current of the battery input, and because there are no idle devices in the circuit when the circuit is in the battery working mode, the circuit utilization rate is improved.

[0041] The embodiment of the present invention provides a rectifier circuit, which includes six first switch modules, six second switch modules and six bridge arm units, wherein the six bridge arm units are respectively a first bridge arm unit, a second bridge arm unit, a third bridge arm unit, a fourth bridge arm unit, a fifth bridge arm unit and a sixth bridge arm unit; the first bridge arm unit and the second bridge arm unit are respectively connected to the first phase of the alternating current through two first switch modules, the third bridge arm unit and the fourth bridge arm unit are respectively connected to the second phase of the alternating current through two first switch modules, and the fifth bridge arm unit and the sixth bridge arm unit are respectively connected to the third phase of the alternating current through two first switch modules; the first bridge arm unit, the second bridge arm unit and the third bridge arm unit are respectively connected to the first pole of the battery through three second switch modules, and the fourth bridge arm unit, the fifth bridge arm unit and the sixth bridge arm unit are respectively connected to the second pole of the battery through three second switch modules, and the first pole of the battery and the second pole of the battery of the entire main power circuit are separated to avoid crossing, so that when designing the circuit board, the distance between the first pole of the battery and the second pole of the battery can be designed to be very large, which can greatly reduce the risk of battery arcing and fire. The present invention can realize that when the circuit is in the AC working mode and the battery working mode, different bridge arm units can be controlled to be independently turned on, so that the conduction time of different bridge arm units is out of phase, thereby reducing the ripple current of the AC input and the ripple current of the battery input. In addition, since there are no idle devices in the circuit when the circuit is in the battery working mode, the circuit utilization rate is improved.

[0042] Optional, reference Figure 2 The rectifier circuit also includes a first capacitor C1 and a second capacitor C2.

[0043] Each bridge arm unit includes two diodes, an inductor and a combination switch, the two diodes are respectively a first diode and a second diode, the input end of the first diode is connected to the output end of the second diode, the connection between the first diode and the second diode is respectively connected to the first port of the inductor and the first port of the combination switch, and the second port of the combination switch is connected to the neutral line N; the output end of the first diode is connected to the first port of the first capacitor, the input end of the second diode is connected to the first port of the second capacitor, and the second port of the first capacitor is connected to the second port of the second capacitor and the neutral line N.

[0044] Among them, the second port of the inductor of the first bridge arm unit M1 and the second bridge arm unit M2 is connected to the first phase 201 of the alternating current and the first pole of the battery, the second port of the inductor of the third bridge arm unit M3 is connected to the second phase 202 of the alternating current and the first pole of the battery, the second port of the inductor of the fourth bridge arm unit M4 is connected to the second phase 202 of the alternating current and the second pole of the battery, and the second port of the inductor of the fifth bridge arm unit M5 and the sixth bridge arm unit M6 is connected to the third phase 203 of the alternating current and the second pole of the battery. The alternating current is the mains, and the combination switches Q1-Q6 are all switch tube combinations, which can have multiple combination forms.

[0045] Specifically, Figure 2 As shown, the first bridge arm unit M1 includes a combination switch Q1, an inductor L1, a first diode D1 and a second diode D2, the input end of the first diode D1 is connected to the output end of the second diode D2, the connection between the first diode D1 and the second diode D2 is respectively connected to the first port of the inductor L1 and the first port of the combination switch Q1, and the second port of the combination switch Q1 is connected to the neutral line N; the output end of the first diode D1 is connected to the first port of the first capacitor C1, the input end of the second diode D2 is connected to the first port of the second capacitor C2, and the second port of the first capacitor C1 is connected to the second port of the second capacitor C2 and the neutral line N. The second port of the inductor L1 of the first bridge arm unit M1 is connected to the first phase 201 of the alternating current and the first pole of the battery.

[0046] The second bridge arm unit M2 includes a combination switch Q2, an inductor L2, a first diode D3 and a second diode D4, and the second port of the inductor L2 of the second bridge arm unit M2 is connected to the first phase 201 of the alternating current and the first pole of the battery. The connection method of the internal components of the second bridge arm unit M2 is the same as the connection method of the components of the first bridge arm unit M1, which will not be repeated here.

[0047] The third bridge arm unit M3 includes a combination switch Q3, an inductor L3, a first diode D5 and a second diode D6, and the second port of the inductor L3 of the third bridge arm unit M3 is connected to the second phase 202 of the alternating current and the first pole of the battery. The connection method of the internal components of the third bridge arm unit M3 is the same as the connection method of the components of the first bridge arm unit M1, which will not be repeated here.

[0048] The fourth bridge arm unit M4 includes a combination switch Q4, an inductor L4, a first diode D7 and a second diode D8, and the second port of the inductor L4 of the fourth bridge arm unit M4 is connected to the second phase 202 of the alternating current and the second pole of the battery. The connection method of the internal components of the fourth bridge arm unit M4 is the same as the connection method of the components of the first bridge arm unit M1, which will not be repeated here.

[0049] The fifth bridge arm unit M5 includes a combination switch Q5, an inductor L5, a first diode D9 and a second diode D10, and the second port of the inductor L5 of the fifth bridge arm unit M5 is connected to the third phase 203 of the alternating current and the second pole of the battery. The connection method of the internal components of the fifth bridge arm unit M5 is the same as the connection method of the components of the first bridge arm unit M1, which will not be repeated here.

[0050] The sixth bridge arm unit M6 includes a combination switch Q6, an inductor L6, a first diode D11 and a second diode D12, and the second port of the inductor L6 of the sixth bridge arm unit M6 is connected to the third phase 203 of the alternating current and the second pole of the battery. The connection method of the internal components of the sixth bridge arm unit M6 is the same as the connection method of the components of the first bridge arm unit M1, and will not be repeated here. In the embodiment of the present invention, since the following rectifier circuit structure is set: the first phase 201 of the alternating current is connected to the first bridge arm unit M1 and the second bridge arm unit M2, the second phase 202 of the alternating current is connected to the third bridge arm unit M3 and the fourth bridge arm unit M4, the third phase 203 of the alternating current is connected to the fifth bridge arm unit M5 and the sixth bridge arm unit M6, the first pole of the battery is connected to the first bridge arm unit M1, the second bridge arm unit M2 and the third bridge arm unit M3, and the second pole of the battery is connected to the fourth bridge arm unit M4, the fifth bridge arm unit M5 and the sixth bridge arm unit M6, then in the mains working mode, each phase of the alternating current can be connected to each inductor through the connected bridge arm unit. When AC power is input, capacitors C1 and C2 are charged by staggered opening and closing of the combination switches of the corresponding bridge arm units. The ripple currents of the inductors can offset each other partially, thereby reducing the ripple current of the AC input and reducing the size of the AC input filter. In the battery working mode, each bridge arm unit can charge the capacitor, and there are no idle devices in the circuit, which improves the utilization rate of the devices. In the battery working mode, capacitors C1 and C2 can also be charged by staggered opening and closing of the combination switches of the corresponding bridge arm units. The ripple currents of the inductors can offset each other partially, thereby reducing the ripple current of the battery input and reducing the size of the battery input filter.

[0051] The embodiment of the present invention can realize that when the circuit is in the AC power working mode and the battery working mode, the combination switches in different bridge arm units can be controlled to be independently turned on, so that the conduction time of the combination switches in different bridge arm units is out of phase, thereby reducing the ripple current of the AC power input and the ripple current of the battery input. In addition, since there are no idle devices in the circuit when the circuit is in the battery working mode, the circuit utilization rate is improved.

[0052] Optional, continue to refer to Figure 2 The six first switch modules 301 are switch K2, switch K4, switch K6, switch K8, switch K10, and switch K12, and the six second switch modules 302 are switch K1, switch K3, switch K5, switch K7, switch K9, and switch K11. A first switch module 301 is provided on the line between the second port of the inductor of each bridge arm unit and the alternating current, and the first switch module 301 is used to control the connection between each bridge arm unit and the alternating current. A second switch module 302 is also provided on the line between the second port of the inductor of each bridge arm unit and the battery, and the second switch module 302 is used to control the connection between each bridge arm unit and the battery.

[0053] Specifically, a switch K2 is provided on the connection line between the second port of the inductor L1 of the first bridge arm unit M1 and the first phase 201 of the alternating current, and a switch K1 is also provided on the line between the second port of the inductor L1 of the first bridge arm unit M1 and the first pole of the battery. The switch K2 is used to control the connection between the first bridge arm unit M1 and the first phase 201 of the alternating current, and the switch K1 is used to control the connection between the first bridge arm unit M1 and the first pole of the battery.

[0054] A switch K4 is provided on the connection line between the second port of the inductor L2 of the second bridge arm unit M2 and the first phase 201 of the alternating current, and a switch K3 is also provided on the line between the second port of the inductor L1 of the second bridge arm unit M2 and the first pole of the battery. The switch K4 is used to control the connection between the second bridge arm unit M2 and the first phase 201 of the alternating current, and the switch K3 is used to control the connection between the second bridge arm unit M2 and the first pole of the battery.

[0055] A switch K6 is provided on the connection line between the second port of the inductor L3 of the third bridge arm unit M3 and the second phase 202 of the alternating current, and a switch K5 is also provided on the line between the second port of the inductor L3 of the third bridge arm unit M3 and the first pole of the battery. The switch K6 is used to control the connection between the third bridge arm unit M3 and the second phase 202 of the alternating current, and the switch K5 is used to control the connection between the third bridge arm unit M3 and the first pole of the battery.

[0056] A switch K8 is provided on the connection line between the second port of the inductor L4 of the fourth bridge arm unit M4 and the second phase 202 of the alternating current, and a switch K7 is also provided on the line between the second port of the inductor L4 of the fourth bridge arm unit M4 and the second pole of the battery. The switch K8 is used to control the connection between the fourth bridge arm unit M4 and the second phase 202 of the alternating current, and the switch K7 is used to control the connection between the fourth bridge arm unit M4 and the second pole of the battery.

[0057] A switch K10 is provided on the connection line between the second port of the inductor L5 of the fifth bridge arm unit M5 and the third phase 203 of the alternating current, and a switch K9 is also provided on the line between the second port of the inductor L5 of the fifth bridge arm unit M5 and the second pole of the battery. The switch K10 is used to control the connection between the fifth bridge arm unit M5 and the third phase 203 of the alternating current, and the switch K9 is used to control the connection between the fifth bridge arm unit M5 and the second pole of the battery.

[0058] A switch K12 is provided on the connection line between the second port of the inductor L6 of the sixth bridge arm unit M6 and the third phase 203 of the alternating current, and a switch K11 is also provided on the line between the second port of the inductor L6 of the sixth bridge arm unit M6 and the second pole of the battery. The switch K12 is used to control the connection between the sixth bridge arm unit M6 and the third phase 203 of the alternating current, and the switch K11 is used to control the connection between the sixth bridge arm unit M6 and the second pole of the battery.

[0059] A first switch module 301 is provided on the line between the second port of the inductor of each bridge arm unit and the alternating current, and the first switch module 301 is used to control the connection between each bridge arm unit and the alternating current. A second switch module 302 is also provided on the line between the second port of the inductor of each bridge arm unit and the battery, and the second switch module 302 is used to control the connection between each bridge arm unit and the battery, so that the bridge arm unit can switch between connecting to the mains and the battery, thereby controlling the working mode of the rectifier circuit. In the AC working mode, by controlling the conduction of switch K2, switch K4, switch K6, switch K8, switch K10 and switch K12, the first bridge arm unit M1 and the second bridge arm unit M2 are controlled to be connected to the first phase 201 of the alternating current, the third bridge arm unit M3 and the fourth bridge arm unit M4 are controlled to be connected to the second phase 202 of the alternating current, and the fifth bridge arm unit M5 and the sixth bridge arm unit M6 are controlled to be connected to the third phase 203 of the alternating current; in the battery working mode, by controlling the conduction of switch K1, switch K3, switch K5, switch K7, switch K9 and switch K11, the first bridge arm unit M1 and the second bridge arm unit M2 are controlled to be connected to the first pole of the battery, the third bridge arm unit M3 is controlled to be connected to the first pole of the battery, the fourth bridge arm unit M4 is controlled to be connected to the second pole of the battery, and the fifth bridge arm unit M5 and the sixth bridge arm unit M6 are controlled to be connected to the second pole of the battery.

[0060] Optional, Figure 3 A schematic diagram of the structure of a combination switch provided by an embodiment of the present invention, Figure 4 A structural diagram of another combination switch provided by an embodiment of the present invention is shown in FIG. Figure 3 and Figure 4 As shown, the combination switch includes two switching tubes connected in series.

[0061] Specifically, Figure 3 As shown, the two series-connected switch tubes may be two series-connected field effect tubes B1, and the conduction and disconnection of the combined switch are controlled by controlling the conduction and disconnection of the two series-connected field effect tubes B1. Figure 4As shown, the two series-connected switch tubes may also be two series-connected insulated-gate bipolar transistors (IGBT) C1. By controlling the on and off of the two series-connected insulated-gate bipolar transistors C1, the on and off of the combined switch is controlled.

[0062] Optional, Figure 5 A structural diagram of another combination switch provided by an embodiment of the present invention is shown in FIG. Figure 5 As shown, the combined switch includes a switch tube E1, a third diode d1, a fourth diode d2, a fifth diode d3 and a sixth diode d4.

[0063] The first end of the third diode d1 is connected to the second end of the fourth diode d2, and the connection point of the third diode d1 and the fourth diode d2 serves as the first port of the combined switch; the second end of the third diode d1 and the fifth diode d3 are connected to the second end of the switch triode E1, the second end of the fourth diode d2 and the sixth diode d4 are connected to the third end of the switch tube E1, and the first end of the switch tube E1 is the control end; the first end of the fifth diode d3 is connected to the second end of the sixth diode d4, and the connection point of the fifth diode d3 and the sixth diode d4 serves as the first port of the combined switch.

[0064] Specifically, the switch tube E1 may be an insulated gate bipolar transistor. By controlling the on and off of the switch tube E1, the on and off of the combined switch may be controlled.

[0065] Optional, Figure 6 A control schematic diagram of a control unit provided in an embodiment of the present invention, such as Figure 6 As shown, the rectifier circuit further includes a control unit 200, which is connected to each combination switch; the control unit 200 is used to send a control signal to each combination switch to control the on and off of each combination switch.

[0066] Among them, Figure 6As shown, the control unit 200 is connected to the combination switch Q1, the combination switch Q2, the combination switch Q3, the combination switch Q4, the combination switch Q5 and the combination switch Q6. The control signal sent by the control unit 200 includes a PWM control signal (Pulse Width Modulation, PWM) corresponding to each combination switch. The PWM control signal controls the conduction of the corresponding combination switch, and the carrier signal is used to assist in controlling the frequency and duty cycle of the corresponding PWM control signal. It should be noted that PWM is a technology that controls the average power of the output signal by changing the duty cycle of the pulse signal. The PWM technology equivalently obtains the required waveform, including shape and amplitude, through a series of pulse width modulation. The PWM waveform consists of a series of square wave pulses, and the width of each pulse can be adjusted as needed. The types of carriers corresponding to PWM mainly include triangular waves and sawtooth waves. As carrier signals, the frequencies of triangular waves and sawtooth waves are usually much higher than the frequency of the reference signal. In the sinusoidal pulse width modulation (SPWM) technology, the carrier signal is compared with the reference sine wave signal, and a PWM pulse signal is generated according to the comparison result. The width and frequency of these PWM pulse signals change with the reference sine wave signal, thereby realizing the control of the output waveform. Since the PWM control signal is generated by the corresponding carrier signal, by controlling the phase difference of the carrier signal corresponding to each combination switch, the corresponding combination switch can be staggered to open and close by the PWM control signal corresponding to each combination switch.

[0067] In the embodiment of the present invention, the control unit 200 can control the conduction and disconnection of each combination switch by sending a control signal to each combination switch. In the mains working mode, each phase of the alternating current can input the alternating current to each inductor through the connected bridge arm unit, and the control unit 200 controls the staggered opening and closing of the combination switch of the corresponding bridge arm unit to charge the capacitors C1 and C2, thereby greatly reducing the ripple current of the mains input and reducing the volume of the mains input filter. In the battery working mode, the control unit 200 can also control the staggered opening and closing of the combination switch of the corresponding bridge arm unit to charge the capacitors C1 and C2, thereby greatly reducing the ripple current of the battery input and reducing the volume of the battery input filter.

[0068] Optional, Figure 7 A schematic diagram of the waveform of the control signal of each combination switch in the mains working mode provided by the embodiment of the present invention, such as Figure 7As shown, in the mains working mode, the control unit 200 sends the PWM control signal corresponding to each combination switch respectively; wherein, in the mains working mode, the carrier signal corresponding to the combination switch Q1 of the first bridge arm unit M1 and the carrier signal corresponding to the combination switch Q2 of the second bridge arm unit M2 are out of phase by 180 degrees, the carrier signal corresponding to the combination switch Q3 of the third bridge arm unit M3 and the carrier signal corresponding to the combination switch Q4 of the fourth bridge arm unit M4 are out of phase by 180 degrees, the carrier signal corresponding to the combination switch Q5 of the fifth bridge arm unit M5 and the carrier signal corresponding to the combination switch Q6 of the sixth bridge arm unit M6 are out of phase by 180 degrees; and the carrier signal corresponding to the combination switch Q1 of the first bridge arm unit M1, the carrier signal corresponding to the combination switch Q3 of the third bridge arm unit M3 and the carrier signal corresponding to the combination switch Q5 of the fifth bridge arm unit M5 are out of phase by 120 degrees, the carrier signal corresponding to the combination switch Q2 of the second bridge arm unit M2, the carrier signal corresponding to the combination switch Q4 of the fourth bridge arm unit M4 and the carrier signal corresponding to the combination switch Q6 of the sixth bridge arm unit M6 are out of phase by 120 degrees.

[0069] Specifically, in the mains working mode, if Figure 7 As shown, the carrier signal phase corresponding to the combination switch Q1 of the first bridge arm unit M1 is 0°, the carrier signal phase corresponding to the combination switch Q2 of the second bridge arm unit M2 is 180°, the carrier signal phase corresponding to the combination switch Q3 of the third bridge arm unit M3 is 120°, the carrier signal phase corresponding to the combination switch Q4 of the fourth bridge arm unit M4 is 300°, the carrier signal phase corresponding to the combination switch Q5 of the fifth bridge arm unit M5 is 240°, and the carrier signal phase corresponding to the combination switch Q6 of the sixth bridge arm unit M6 is 60°, that is, the carrier signal corresponding to the combination switch Q1 of the first bridge arm unit M1, the carrier signal corresponding to the combination switch Q3 of the third bridge arm unit M3, and the carrier signal corresponding to the combination switch Q5 of the fifth bridge arm unit M5 are 60°. The corresponding carrier signals are out of phase by 120 degrees, and the carrier signals corresponding to the combination switch Q2 of the second bridge arm unit M2, the carrier signals corresponding to the combination switch Q4 of the fourth bridge arm unit M4, and the carrier signals corresponding to the combination switch Q6 of the sixth bridge arm unit M6 are out of phase by 120 degrees. Then, the phase-shifting amplitude of the PWM control signals corresponding to the combination switches is the same as the phase-shifting amplitude of the carrier signals, thereby realizing staggered opening and closing of the combination switches controlled by the PWM control signals. The capacitors C1 and C2 are charged by the method of controlling the staggered opening and closing of the combination switches of the corresponding bridge arm units by the control unit 200, and the ripple currents of the inductors can offset each other partially, thereby greatly reducing the ripple current of the AC input and reducing the volume of the AC input filter.

[0070] Optional, Figure 8 A schematic diagram of the waveforms of the control signals of the various combination switches in the battery working mode provided by the embodiment of the present invention, such as Figure 8As shown, in the battery working mode, the control unit 200 sends the PWM control signal corresponding to each combination switch respectively; wherein, in the battery working mode, the carrier signal corresponding to the combination switch Q1 of the first bridge arm unit M1 is synchronized with the carrier signal corresponding to the combination switch Q4 of the fourth bridge arm unit M4, the carrier signal corresponding to the combination switch Q2 of the second bridge arm unit M2 is synchronized with the carrier signal corresponding to the combination switch Q5 of the fifth bridge arm unit M5, the carrier signal corresponding to the combination switch Q3 of the third bridge arm unit M3 is synchronized with the carrier signal corresponding to the combination switch Q6 of the sixth bridge arm unit M6; and the carrier signal corresponding to the combination switch Q1 of the first bridge arm unit M1, the carrier signal corresponding to the combination switch Q2 of the second bridge arm unit M2, and the carrier signal corresponding to the combination switch Q3 of the third bridge arm unit M3 are staggered by 120 degrees, and the carrier signal corresponding to the combination switch Q4 of the fourth bridge arm unit M4, the carrier signal corresponding to the combination switch Q5 of the fifth bridge arm unit M5, and the carrier signal corresponding to the combination switch Q6 of the sixth bridge arm unit M6 are staggered by 120 degrees.

[0071] Specifically, Figure 8 As shown, in the battery working mode, the carrier signal phase corresponding to the combination switch Q1 of the first bridge arm unit M1 and the combination switch Q2 of the second bridge arm unit M2 is 0°, the carrier signal phase corresponding to the combination switch Q4 of the third bridge arm unit M3 and the combination switch Q4 of the fourth bridge arm unit M4 is 120°, and the carrier signal phase corresponding to the combination switch Q5 of the fifth bridge arm unit M5 and the combination switch Q6 of the sixth bridge arm unit M6 is 240°, that is, the carrier signal corresponding to the combination switch Q1 of the first bridge arm unit M1 is synchronized with the carrier signal corresponding to the combination switch Q4 of the fourth bridge arm unit M4, and the carrier signal corresponding to the combination switch Q2 of the second bridge arm unit M2 is synchronized with the carrier signal corresponding to the combination switch Q5 of the fifth bridge arm unit M5 and the combination switch Q6 of the sixth bridge arm unit M6. The carrier signal corresponding to the combination switch Q5 of the bridge arm unit M5 is synchronized, the carrier signal corresponding to the combination switch Q3 of the third bridge arm unit M3 and the carrier signal corresponding to the combination switch Q6 of the sixth bridge arm unit M6 are synchronized; and the carrier signal corresponding to the combination switch Q1 of the first bridge arm unit M1, the carrier signal corresponding to the combination switch Q2 of the second bridge arm unit M2 and the carrier signal corresponding to the combination switch Q3 of the third bridge arm unit M3 are staggered by 120 degrees, and the carrier signal corresponding to the combination switch Q4 of the fourth bridge arm unit M4, the carrier signal corresponding to the combination switch Q5 of the fifth bridge arm unit M5 and the carrier signal corresponding to the combination switch Q6 of the sixth bridge arm unit M6 are staggered by 120 degrees. The phase-shifting amplitude of the PWM control signal corresponding to each combination switch is the same as the phase-shifting amplitude of the carrier signal, so as to realize the staggered opening and closing of each combination switch controlled by the PWM control signal, and the capacitors C1 and C2 are charged by the method of controlling the staggered opening and closing of the combination switch of the corresponding bridge arm unit by the control unit 200, and the ripple current of the inductor can offset each other partially, greatly reducing the ripple current of the battery input and reducing the volume of the battery input filter.

[0072] Optional, Fig. 9 The timing diagram of switching from the mains working mode to the battery working mode provided by the embodiment of the present invention is as follows: Fig. 9 As shown, when the AC working mode is switched to the battery working mode, the control unit 200 first turns off the driving of the combination switches in each bridge arm unit, stops sending the PWM control signals corresponding to each combination switch in the AC working mode, and after the first time t1, the control unit 200 disconnects the connection between each phase of the AC power and the bridge arm unit, and exits the AC working mode; after the second time period t2, the connection between the two poles of the battery and the bridge arm unit is established; after the third time t3, the control unit 200 turns on the driving of each combination switch, sends the PWM control signals corresponding to each combination switch in the battery working mode, and enters the battery working mode.

[0073] Among them, the AC relay can control the output of AC power. When the AC relay is disconnected, each phase of the AC power stops outputting current. The battery relay can control the connection between the two poles of the battery and the bridge arm unit. When the battery relay is turned on, the connection between the two poles of the battery and the bridge arm unit is established. The control unit 200 is provided with a combination switch Q1 to a combination switch Q6 drive. When the combination switch Q1 to the combination switch Q6 drive is turned on, the PWM control signal corresponding to each combination switch is sent. When the combination switch Q1 to the combination switch Q6 drive is turned off, the PWM control signal corresponding to each combination switch is stopped.

[0074] Specifically, the first time t1 is the time from closing the combination switch Q1 to the combination switch Q6 to closing the mains relay. The control unit 200 first closes the drive of the combination switch in each bridge arm unit, stops sending the PWM control signal corresponding to each combination switch in the mains working mode, and after the first time t1, disconnects the connection between each phase of the AC power and the bridge arm unit, and exits the mains working mode. The effect of the first time t1: after closing the combination switch Q1 to the combination switch Q6, the current of the inductor L1 to the inductor L6 naturally drops to zero, and the current of the mains relay also drops to zero, and then the battery relay is actuated to ensure that the mains relay is shut down with zero current. The second time t2 is the time from closing the mains relay to opening the battery relay. After the second time t2, the connection between the two poles of the battery and the bridge arm unit is established through the battery relay. The effect of the second time t2: after ensuring that the mains relay is reliably shut down, the battery relay is turned on to prevent the battery and the mains from being directly connected. The third time t3 is the time from turning on the battery relay to turning on the combination switch Q1 to the combination switch Q6. The function of the third time t3 is to ensure that after the battery relay is reliably closed and opened, the combination switches Q1 to Q6 are driven, that is, after the third time t3, the driving of each combination switch is turned on, and the PWM control signal corresponding to each combination switch in the battery working mode is sent to enter the battery working mode.

[0075] Optional, Fig.10 The timing diagram of switching from the battery working mode to the mains working mode provided by the embodiment of the present invention is as follows: Fig.10 As shown, when the battery working mode is switched to the AC power working mode, the control unit 200 first turns off the drive of the combination switches in each bridge arm unit, stops sending the PWM control signals corresponding to each combination switch in the battery working mode, and after the fourth time t4, disconnects the two poles of the battery from the bridge arm unit, and exits the battery working mode; after the fifth time t5, establishes the connection between each phase of the AC power and the bridge arm unit; after the sixth time t6, turns on the drive of each combination switch, sends the PWM control signals corresponding to each combination switch in the AC power working mode, and enters the AC power working mode.

[0076] Specifically, the fourth time t4 has the same function as the first time t1, which can ensure that the battery relay is shut down with zero current; the fifth time t5 has the same function as the second time t2, which prevents direct connection between the battery and the AC power; the sixth time t6 has the same function as the third time t3, which ensures that the AC power relay is reliably closed and opened before turning on the combination switch Q1 to the combination switch Q6.

[0077] In addition, in the embodiment of the present invention, the rectifier circuit includes six bridge arm units, that is, the rectifier circuit includes six bridge arms. In the mains working mode and the battery working mode, the multiplexing degree of the rectifier circuit becomes higher, which can reduce the number of components, volume and cost in the uninterruptible power supply where the rectifier circuit is located. In the mains working mode, all bridge arms are used, and the power of each bridge arm is the same; in the battery working mode, all bridge arms are also used, and the power of each bridge arm is also the same. This setting makes the utilization rate of the rectifier circuit the highest.

[0078] The embodiment of the present invention provides a rectifier circuit, which separates the positive and negative of the battery in the entire main power circuit to avoid crossover. In this way, when designing the circuit board, the distance between the positive and negative of the battery can be designed to be large, which can greatly reduce the risk of battery arcing and fire. The present invention can realize that when the circuit is in the mains working mode and the battery working mode, the combination switches in different bridge arm units can be controlled to be independently turned on, so that the conduction time of the combination switches in different bridge arm units is out of phase, thereby greatly reducing the ripple current of the mains input and the ripple current of the battery input, and because the circuit does not have idle devices when the circuit is in the battery working mode, the circuit utilization rate is improved.

[0079] The embodiment of the present invention further provides a control method for a rectifier circuit. The control method for a rectifier circuit is used to control the rectifier circuit of any embodiment of the present invention. The control method is executed by the control unit 200 of the rectifier circuit to achieve the same technical effect as the rectifier circuit. Fig.11A flow chart of a control method for a rectifier circuit provided in an embodiment of the present invention, such as Fig.11 As shown, the control method of the rectifier circuit includes:

[0080] S110. In the AC power working mode, the first bridge arm unit and the second bridge arm unit are controlled to be connected to the first phase of the AC power, the third bridge arm unit and the fourth bridge arm unit are controlled to be connected to the second phase of the AC power, and the fifth bridge arm unit and the sixth bridge arm unit are controlled to be connected to the third phase of the AC power.

[0081] Specifically, refer to Figure 2 , the rectifier circuit includes twelve switches, a switch is provided on the line between the second port of the inductor of each bridge arm unit and the mains, and a switch is also provided on the line between the second port of the inductor of each bridge arm unit and the battery, and the switch is used to control the connection of each bridge arm unit with the mains and the battery. In the mains working mode, by controlling the conduction of switch K2, switch K4, switch K6, switch K8, switch K10 and switch K12, the first bridge arm unit M1 and the second bridge arm unit M2 are controlled to be connected to the first phase 201 of the alternating current, the third bridge arm unit M3 and the fourth bridge arm unit M4 are controlled to be connected to the second phase 202 of the alternating current, and the fifth bridge arm unit M5 and the sixth bridge arm unit M6 are controlled to be connected to the third phase 203 of the alternating current, and the alternating current is the mains, so that in the mains working mode, each phase of the alternating current can input the alternating current to each inductor through the connected bridge arm unit, and the capacitors C1 and C2 are charged by the method of staggered opening and closing of the combined switches of the corresponding bridge arm units, which greatly reduces the ripple current of the mains input and reduces the volume of the mains input filter.

[0082] S120. In the battery working mode, the first bridge arm unit and the second bridge arm unit are controlled to be connected to the first pole of the battery, the third bridge arm unit is controlled to be connected to the first pole of the battery, the fourth bridge arm unit is controlled to be connected to the second pole of the battery, and the fifth bridge arm unit and the sixth bridge arm unit are controlled to be connected to the second pole of the battery.

[0083] Specifically, in the battery working mode, by controlling the conduction of switch K1, switch K3, switch K5, switch K7, switch K9 and switch K11, the first bridge arm unit M1 and the second bridge arm unit M2 are controlled to be connected to the first pole of the battery, the third bridge arm unit M3 is controlled to be connected to the first pole of the battery, the fourth bridge arm unit M4 is controlled to be connected to the second pole of the battery, and the fifth bridge arm unit M5 and the sixth bridge arm unit M6 are controlled to be connected to the second pole of the battery, so that in the battery working mode, each bridge arm unit can charge the capacitor, there are no idle devices in the circuit, and the utilization rate of the devices is improved. In the battery working mode, the capacitors C1 and C2 can also be charged by staggered opening and closing of the combination switches of the corresponding bridge arm units, which greatly reduces the ripple current of the battery input and reduces the volume of the battery input filter.

[0084] The embodiment of the present invention provides a control method for a rectifier circuit. In a mains operation mode, the first bridge arm unit and the second bridge arm unit are controlled to be connected to the first phase of the alternating current, the third bridge arm unit and the fourth bridge arm unit are controlled to be connected to the second phase of the alternating current, and the fifth bridge arm unit and the sixth bridge arm unit are controlled to be connected to the third phase of the alternating current; in a battery operation mode, the first bridge arm unit and the second bridge arm unit are controlled to be connected to the first pole of the battery, the third bridge arm unit is controlled to be connected to the first pole of the battery, the fourth bridge arm unit is controlled to be connected to the second pole of the battery, and the fifth bridge arm unit and the sixth bridge arm unit are controlled to be connected to the second pole of the battery. This realizes that when the circuit is in the mains operation mode and the battery operation mode, the combination switches in different bridge arm units can be controlled to be independently turned on, so that the conduction time of the combination switches in different bridge arm units is out of phase, thereby greatly reducing the ripple current of the mains input and the ripple current of the battery input. In addition, since there are no idle devices in the circuit when the circuit is in the battery operation mode, the circuit utilization rate is improved.

[0085] Optionally, the control method of the rectifier circuit further includes: in the mains working mode, sending PWM control signals corresponding to each combination switch respectively.

[0086] Among them, in the AC power working mode, the carrier signal corresponding to the combination switch of the first bridge arm unit and the carrier signal corresponding to the combination switch of the second bridge arm unit are out of phase by 180 degrees, the carrier signal corresponding to the combination switch of the third bridge arm unit and the carrier signal corresponding to the combination switch of the fourth bridge arm unit are out of phase by 180 degrees, and the carrier signal corresponding to the combination switch of the fifth bridge arm unit and the carrier signal corresponding to the combination switch of the sixth bridge arm unit are out of phase by 180 degrees; and the carrier signal corresponding to the combination switch of the first bridge arm unit, the carrier signal corresponding to the combination switch of the third bridge arm unit and the carrier signal corresponding to the combination switch of the fifth bridge arm unit are out of phase by 120 degrees, and the carrier signal corresponding to the combination switch of the second bridge arm unit, the carrier signal corresponding to the combination switch of the fourth bridge arm unit and the carrier signal corresponding to the combination switch of the sixth bridge arm unit are out of phase by 120 degrees.

[0087] Specifically, the control unit 200 is connected to each combination switch; the control unit 200 is used to send a control signal to each combination switch to control the on and off of each combination switch. Figure 7As shown, the carrier signal phase corresponding to the combination switch Q1 of the first bridge arm unit M1 is 0°, the carrier signal phase corresponding to the combination switch Q2 of the second bridge arm unit M2 is 180°, the carrier signal phase corresponding to the combination switch Q3 of the third bridge arm unit M3 is 120°, the carrier signal phase corresponding to the combination switch Q4 of the fourth bridge arm unit M4 is 300°, the carrier signal phase corresponding to the combination switch Q5 of the fifth bridge arm unit M5 is 240°, and the carrier signal phase corresponding to the combination switch Q6 of the sixth bridge arm unit M6 is 60°. Then, the phase-shifting amplitude of the PWM control signal corresponding to each combination switch is the same as the phase-shifting amplitude of the carrier signal, thereby realizing the staggered opening and closing of each combination switch controlled by the PWM control signal. The capacitors C1 and C2 are charged by the method of controlling the staggered opening and closing of the combination switch of the corresponding bridge arm unit by the control unit 200, and the ripple current of the inductor can offset each other partially, thereby greatly reducing the ripple current of the mains input and reducing the volume of the mains input filter.

[0088] Optionally, the control method of the rectifier circuit further includes: in a battery working mode, sending PWM control signals corresponding to each combination switch respectively.

[0089] Among them, in the battery working mode, the carrier signal corresponding to the combination switch of the first bridge arm unit is synchronized with the carrier signal corresponding to the combination switch of the fourth bridge arm unit, the carrier signal corresponding to the combination switch of the second bridge arm unit is synchronized with the carrier signal corresponding to the combination switch of the fifth bridge arm unit, and the carrier signal corresponding to the combination switch of the third bridge arm unit is synchronized with the carrier signal corresponding to the combination switch of the sixth bridge arm unit; and the carrier signal corresponding to the combination switch of the first bridge arm unit, the carrier signal corresponding to the combination switch of the second bridge arm unit, and the carrier signal corresponding to the combination switch of the third bridge arm unit are out of phase by 120 degrees, and the carrier signal corresponding to the combination switch of the fourth bridge arm unit, the carrier signal corresponding to the combination switch of the fifth bridge arm unit, and the carrier signal corresponding to the combination switch of the sixth bridge arm unit are out of phase by 120 degrees.

[0090] Specifically, Figure 8As shown, in the battery working mode, the carrier signal phase corresponding to the combination switch Q1 of the first bridge arm unit M1 and the combination switch Q2 of the second bridge arm unit M2 is 0°, the carrier signal phase corresponding to the combination switch Q4 of the third bridge arm unit M3 and the combination switch Q4 of the fourth bridge arm unit M4 is 120°, and the carrier signal phase corresponding to the combination switch Q5 of the fifth bridge arm unit M5 and the combination switch Q6 of the sixth bridge arm unit M6 is 240°. The phase-shifting amplitude of the PWM control signal corresponding to each combination switch is the same as the phase-shifting amplitude of the carrier signal, so as to realize the staggered opening and closing of each combination switch controlled by the PWM control signal, and the capacitors C1 and C2 are charged by the method of controlling the staggered opening and closing of the combination switch of the corresponding bridge arm unit by the control unit 200, and the ripple current of the inductor can offset each other partially, greatly reducing the ripple current of the battery input and reducing the volume of the battery input filter.

[0091] Optionally, the control method of the rectifier circuit further includes:

[0092] When switching the AC working mode to the battery working mode, first turn off the drive of the combination switches in each bridge arm unit, stop sending the PWM control signals corresponding to each combination switch in the AC working mode, and after a first time, disconnect the phases of the AC power from the bridge arm unit, and exit the AC working mode; after a second time period, establish the connection between the two poles of the battery and the bridge arm unit; after a third time, turn on the drive of each combination switch, send the PWM control signals corresponding to each combination switch in the battery working mode, and enter the battery working mode.

[0093] Among them, the connection between each phase of the AC power and the bridge arm unit can be controlled by the AC power relay. When the AC power relay is disconnected, the connection between each phase of the AC power and the bridge arm unit is disconnected, and the output of AC current to the bridge arm unit is stopped. The connection between the two poles of the battery and the bridge arm unit can be controlled by the battery relay. When the battery relay is turned on, the connection between the two poles of the battery and the bridge arm unit is established. The control unit 200 is provided with a combination switch Q1 to a combination switch Q6 drive. When the combination switch Q1 to the combination switch Q6 drive is turned on, the PWM control signal corresponding to each combination switch is sent. When the combination switch Q1 to the combination switch Q6 drive is turned off, the sending of the PWM control signal corresponding to each combination switch is stopped.

[0094] Specifically, Fig. 9As shown, the first time t1 is the time from closing the combination switch Q1 to the combination switch Q6 to closing the AC relay. The control unit 200 first closes the drive of the combination switch in each bridge arm unit and stops sending the PWM control signal corresponding to each combination switch in the AC working mode. After the first time t1, the AC relay can disconnect the connection between each phase of the AC power and the bridge arm unit, and exit the AC working mode. The role of the first time t1: After closing the combination switch Q1 to the combination switch Q6, the current of the inductor L1 to the inductor L6 naturally drops to zero, and the current of the AC relay also drops to zero, and then the AC relay is actuated to ensure that the AC relay is shut down with zero current. The second time t2 is the time from closing the AC relay to opening the battery relay. After the second time t2, the connection between the two poles of the battery and the bridge arm unit is established through the battery relay. The role of the second time period t2: After ensuring that the AC relay is reliably shut down, the battery relay is turned on to prevent the battery and the AC from being directly connected. The third time period t3 is the time from turning on the battery relay to turning on the combination switch Q1 to the combination switch Q6. After the third time t3, the driving of each combination switch is turned on, and the PWM control signal corresponding to each combination switch in the battery working mode is sent to enter the battery working mode. The function of the third time period t3 is to ensure that the battery relay is reliably closed and turned on before turning on the combination switch Q1 to the combination switch Q6.

[0095] Optionally, the control method of the rectifier circuit further includes:

[0096] When the battery working mode is switched to the AC power working mode, the driving of the combination switches in each bridge arm unit is first turned off, and the sending of the PWM control signals corresponding to each combination switch in the battery working mode is stopped; after the fourth time, the connection between the two poles of the battery and the bridge arm unit is disconnected, and the battery working mode is exited; after the fifth time, the connection between each phase of the alternating current and the bridge arm unit is established; after the sixth time, the driving of each combination switch is turned on, and the PWM control signals corresponding to each combination switch in the AC power working mode are sent to enter the AC power working mode.

[0097] Specifically, Fig.10As shown, the fourth time t4 has the same effect as the first time t1. The control unit 200 first turns off the driving of the combination switches in each bridge arm unit and stops sending the PWM control signals corresponding to each combination switch in the battery working mode. After the fourth time t4, since the driving of the combination switches Q1 to Q6 is turned off, the current of the inductor L1 to L6 naturally drops to zero, and the current of the battery relay also drops to zero. Then the battery relay is actuated to disconnect the two poles of the battery from the bridge arm unit through the battery relay, which can ensure that the battery relay is turned off with zero current; the fifth time t5 has the same effect as the second time t2. After the fifth time t5, the connection between each phase of the AC power and the bridge arm unit is established through the AC relay. After ensuring that the AC relay is reliably turned off, the battery relay is turned on to prevent the battery and the AC power from being directly connected; the sixth time t6 has the same effect as the third time t3. After the sixth time t6, the driving of each combination switch is turned on, and the PWM control signals corresponding to each combination switch in the AC working mode are sent. After ensuring that the AC relay is reliably closed and opened, the driving of the combination switches Q1 to Q6 is turned on.

[0098] The embodiment of the present invention provides a control method for a rectifier circuit, which can realize that when the circuit is in a mains operating mode and a battery operating mode, the combined switches in different bridge arm units can be controlled to be independently turned on, so that the conduction time of the combined switches in different bridge arm units is out of phase, thereby greatly reducing the ripple current of the mains input and the ripple current of the battery input. In addition, since there are no idle devices in the circuit when the circuit is in the battery operating mode, the circuit utilization rate is improved.

[0099] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A rectifier circuit, characterized in that: The rectifier circuit includes six first switch modules, six second switch modules and six bridge arm units, wherein the six bridge arm units are respectively a first bridge arm unit, a second bridge arm unit, a third bridge arm unit, a fourth bridge arm unit, a fifth bridge arm unit and a sixth bridge arm unit; The first bridge arm unit and the second bridge arm unit are connected to the first phase of the alternating current through two of the first switch modules respectively, the third bridge arm unit and the fourth bridge arm unit are connected to the second phase of the alternating current through two of the first switch modules respectively, and the fifth bridge arm unit and the sixth bridge arm unit are connected to the third phase of the alternating current through two of the first switch modules respectively; The first bridge arm unit, the second bridge arm unit and the third bridge arm unit are connected to the first pole of the battery through three second switch modules respectively, and the fourth bridge arm unit, the fifth bridge arm unit and the sixth bridge arm unit are connected to the second pole of the battery through three second switch modules respectively.

2. The rectifier circuit according to claim 1, characterized in that: The rectifier circuit also includes a first capacitor and a second capacitor; Each of the bridge arm units includes two diodes, an inductor and a combination switch, the two diodes are respectively a first diode and a second diode, the input end of the first diode is connected to the output end of the second diode, the connection between the first diode and the second diode is respectively connected to the first port of the inductor and the first port of the combination switch, and the second port of the combination switch is connected to the neutral line; the output end of the first diode is connected to the first port of the first capacitor, the input end of the second diode is connected to the first port of the second capacitor, and the second port of the first capacitor is connected to the second port of the second capacitor and the neutral line.

3. The rectifier circuit according to claim 2, characterized in that: The combined switch includes two switch tubes connected in series.

4. The rectifier circuit according to claim 2, characterized in that: The combined switch comprises a switch tube, a third diode, a fourth diode, a fifth diode and a sixth diode; The first end of the third diode is connected to the second end of the third diode, and the connection point between the third diode and the third diode serves as the first port of the combination switch; the second end of the third diode and the fifth diode are connected to the second end of the switch tube, the second end of the third diode and the fifth diode are connected to the third end of the switch tube, and the first end of the switch tube is the control end; the first end of the fifth diode is connected to the second end of the fifth diode, and the connection point between the fifth diode and the fifth diode serves as the first port of the combination switch.

5. The rectifier circuit according to claim 2, characterized in that: The rectifier circuit further includes a control unit, which is connected to each of the combination switches; The control unit is used to send a control signal to each of the combination switches to control the on and off of each of the combination switches.

6. A control method for a rectifier circuit, characterized in that: The control method of the rectifier circuit is used to control the rectifier circuit according to any one of claims 1 to 5, comprising: In the mains working mode, the first bridge arm unit and the second bridge arm unit are controlled to be connected to the first phase of the alternating current, the third bridge arm unit and the fourth bridge arm unit are controlled to be connected to the second phase of the alternating current, and the fifth bridge arm unit and the sixth bridge arm unit are controlled to be connected to the third phase of the alternating current; In the battery working mode, the first bridge arm unit and the second bridge arm unit are controlled to be connected to the first pole of the battery, the third bridge arm unit is controlled to be connected to the first pole of the battery, the fourth bridge arm unit is controlled to be connected to the second pole of the battery, and the fifth bridge arm unit and the sixth bridge arm unit are controlled to be connected to the second pole of the battery.

7. The control method of the rectifier circuit according to claim 6, characterized in that: The method further comprises: In the mains operation mode, PWM control signals corresponding to the combination switches are respectively sent; Wherein, in the AC power working mode, the carrier signal corresponding to the combination switch of the first bridge arm unit and the carrier signal corresponding to the combination switch of the second bridge arm unit are out of phase by 180 degrees, the carrier signal corresponding to the combination switch of the third bridge arm unit and the carrier signal corresponding to the combination switch of the fourth bridge arm unit are out of phase by 180 degrees, and the carrier signal corresponding to the combination switch of the fifth bridge arm unit and the carrier signal corresponding to the combination switch of the sixth bridge arm unit are out of phase by 180 degrees; and the carrier signal corresponding to the combination switch of the first bridge arm unit, the carrier signal corresponding to the combination switch of the third bridge arm unit and the carrier signal corresponding to the combination switch of the fifth bridge arm unit are out of phase by 120 degrees, and the carrier signal corresponding to the combination switch of the second bridge arm unit, the carrier signal corresponding to the combination switch of the fourth bridge arm unit and the carrier signal corresponding to the combination switch of the sixth bridge arm unit are out of phase by 120 degrees.

8. The control method of the rectifier circuit according to claim 6, characterized in that: The method further comprises: In the battery working mode, respectively sending PWM control signals corresponding to the combination switches; Wherein, in the battery working mode, the carrier signal corresponding to the combination switch of the first bridge arm unit is synchronized with the carrier signal corresponding to the combination switch of the fourth bridge arm unit, the carrier signal corresponding to the combination switch of the second bridge arm unit is synchronized with the carrier signal corresponding to the combination switch of the fifth bridge arm unit, and the carrier signal corresponding to the combination switch of the third bridge arm unit is synchronized with the carrier signal corresponding to the combination switch of the sixth bridge arm unit; and the carrier signal corresponding to the combination switch of the first bridge arm unit, the carrier signal corresponding to the combination switch of the second bridge arm unit, and the carrier signal corresponding to the combination switch of the third bridge arm unit are out of phase by 120 degrees, and the carrier signal corresponding to the combination switch of the fourth bridge arm unit, the carrier signal corresponding to the combination switch of the fifth bridge arm unit, and the carrier signal corresponding to the combination switch of the sixth bridge arm unit are out of phase by 120 degrees.

9. The control method of the rectifier circuit according to claim 6, characterized in that: The method further comprises: When the AC working mode is switched to the battery working mode, the driving of the combination switches in each of the bridge arm units is first turned off, and the sending of the PWM control signals corresponding to each of the combination switches in the AC working mode is stopped; after a first time, the connection between each phase of the AC power and the bridge arm unit is disconnected, and the AC working mode is exited; after a second time, the connection between the two poles of the battery and the bridge arm unit is established; after a third time, the driving of each of the combination switches is turned on, and the PWM control signals corresponding to each of the combination switches in the battery working mode are sent, and the battery working mode is entered.

10. The control method of the rectifier circuit according to claim 6, characterized in that: The method further comprises: When the battery working mode is switched to the AC power working mode, firstly, the driving of the combination switches in each of the bridge arm units is turned off, and the sending of the PWM control signals corresponding to each of the combination switches in the battery working mode is stopped; after a fourth time, the connection between the two poles of the battery and the bridge arm unit is disconnected, and the battery working mode is exited; after a fifth time, the connection between each phase of the alternating current and the bridge arm unit is established; after a sixth time, the driving of each of the combination switches is turned on, and the PWM control signals corresponding to each of the combination switches in the AC power working mode are sent, and the AC power working mode is entered.

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