Bidirectional power supply pre-charge circuit and device

Abstract

The utility model relates to a bidirectional power supply pre-charging circuit and equipment. The circuit comprises a relay module, an input switching control module, a power module and a pre-charging module. The relay module comprises a first relay corresponding to a, a second relay corresponding to b and a third relay corresponding to c, and the relay module is respectively connected with the input switching control module, the power module and the pre-charging module; and the input switching control module is used for controlling opening and closing of the first relay, the second relay and the third relay so as to realize switching between the pre-charging module and the power module. According to the bidirectional power supply pre-charging circuit, the problem of high-frequency current crosstalk can be solved, the design cost is reduced, and the equipment size is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic power technical field especially, it is a kind of two-way power pre-charging circuit and equipment. BACKGROUND

[0002] With the popularity of power equipment, the demand for charging power of chargeable equipment such as electric cars is increasing. The existing two-way power or three-phase charging module widely uses three-phase totem column bridgeless PFC (Power Factor Correction) to improve power efficiency, but due to the existence of pre-charging circuit in the power supply, inductive high-frequency current crosstalk problem will occur, and high-frequency current will be generated, so there is a risk of damage to electrical components. The traditional solution requires the addition of multiple devices and control circuits, which is high in design cost and large in equipment size. UTILITY MODEL CONTENTS

[0003] Therefore, it is necessary to provide a two-way power pre-charging circuit and device that can solve the high-frequency current crosstalk problem while reducing design cost and equipment size.

[0004] In a first aspect, the utility model provides a two-way power pre-charging circuit, which comprises:

[0005] a relay module, an input switching control module, a power module and a pre-charging module;

[0006] The relay module includes a first relay corresponding to phase a, a second relay corresponding to phase b and a third relay corresponding to phase c, and is connected to the input switching control module, the power module and the pre-charging module respectively.

[0007] The input switching control module is used to control the opening and closing of the first relay, the second relay and the third relay to realize the switching between the pre-charging module and the power module.

[0008] In one embodiment, the input switching control module is further used to control the normally closed contact of the first relay, the second relay and the third relay to close and the normally open contact to open to switch from the power module to the pre-charging module when receiving standby instructions.

[0009] In one embodiment, the input switching control module is further used to control the normally closed contact of the first relay, the second relay and the third relay to open and the normally open contact to close to switch from the pre-charging module to the power module when receiving power transmission instructions.

[0010] In one embodiment, the power module includes a first power unit, a second power unit and a third power unit; the pre-charging module includes a first pre-charging unit, a second pre-charging unit and a third pre-charging unit.

[0011] The first pins of the first relay, the second relay and the third relay are grounded respectively;

[0012] The second pins of the first relay, the second relay and the third relay are connected with the first power unit, the second power unit and the third power unit respectively;

[0013] The third pins of the first relay, the second relay and the third relay are connected with the first pre-charge unit, the second pre-charge unit and the third pre-charge unit respectively;

[0014] The fourth pins of the first relay, the second relay and the third relay are connected with the a-phase control signal, the b-phase control signal and the c-phase control signal of the input switching control module respectively;

[0015] The fifth pins of the first relay, the second relay and the third relay are connected with the a-phase, the b-phase and the c-phase of the three-phase alternating current respectively.

[0016] In one of the embodiments, the first power unit comprises a first inductor, a first switch tube and a fourth switch tube; the first end of the first inductor is connected with the second pin of the first relay, and the second end of the first inductor is connected with the first end of the first switch tube and the fourth switch tube respectively;

[0017] The second power unit comprises a second inductor, a second switch tube and a fifth switch tube; the first end of the second inductor is connected with the second pin of the second relay, and the second end of the second inductor is connected with the first end of the second switch tube and the fifth switch tube respectively;

[0018] The third power unit comprises a third inductor, a third switch tube and a sixth switch tube; the first end of the third inductor is connected with the second pin of the third relay, and the second end of the third inductor is connected with the first end of the third switch tube and the sixth switch tube respectively.

[0019] In one of the embodiments, each switch tube is a metal oxide semiconductor field effect transistor.

[0020] In one of the embodiments, the first pre-charge unit comprises a first resistor, a first diode and a fourth diode; the first end of the first resistor is connected with the third pin of the first relay, and the second end of the first resistor is connected with the anode of the first diode and the cathode of the fourth diode respectively;

[0021] The second pre-charge unit comprises a second resistor, a second diode and a fifth diode; the first end of the second resistor is connected with the third pin of the second relay, and the second end of the second resistor is connected with the anode of the second diode and the cathode of the fifth diode respectively;

[0022] The third pre-charging unit comprises a third resistor, a third diode and a sixth diode; a first end of the third resistor is connected with the third pin of the third relay, and a second end of the third resistor is connected with an anode of the third diode and a cathode of the sixth diode respectively.

[0023] In one of the embodiments, the circuit further comprises:

[0024] The output module is connected with the power module and the pre-charging module respectively, and is configured to output the direct current.

[0025] In one of the embodiments, the output module comprises an output capacitor and an output resistor, and the output capacitor is connected with the output resistor in parallel.

[0026] In a second aspect, the utility model provides a kind of bidirectional power pre-charging equipment, including the bidirectional power pre-charging circuit of any one of the embodiment of the first aspect.

[0027] The bidirectional power pre-charging circuit described above, by using only one relay in each phase, completes the switching of the pre-charging module and the power module, can flexibly control the pre-charging module, solves the problem of high-frequency current crosstalk, without adding a relay and a relay control circuit, reduces the design cost and the size of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creative labor.

[0029] Figure 1 It is a bidirectional power pre-charging circuit module of an embodiment;

[0030] Figure 2 It is Figure 1 It is a module structure of the power module 300;

[0031] Figure 3 It is Figure 1 It is a module structure of the pre-charging module 400;

[0032] Figure 4 It is a bidirectional power pre-charging circuit of a specific embodiment.

[0033] Explanation of reference signs:

[0034] 100, relay module; 200, input switch control module; 300, power module; 310, first power unit; 320, second power unit; 330, third power unit; 400, pre-charge module; 410, first pre-charge unit; 420, second pre-charge unit; 430, third pre-charge unit; 500, output module; K1, first relay; K2, second relay; K3, third relay; L1, first inductor; L2, second inductor; L3, third inductor; Q1, first switch tube; Q2, second switch tube; Q3, third switch tube; Q4, fourth switch tube; Q5, fifth switch tube; Q6, sixth switch tube; R1, first resistor; R2, second resistor; R3, third resistor; D1, first diode; D2, second diode; D3, third diode; D4, fourth diode; D5, fifth diode; D6, sixth diode; C, output capacitor; R, output resistor. DETAILED DESCRIPTION

[0035] For the purpose of facilitating the understanding of the present application, a more comprehensive description of the present application will be given below with reference to the relevant drawings. The drawings show embodiments of the present application. However, the present application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the specification of the present application herein is only for the purpose of describing specific embodiments and is not intended to limit the present application.

[0037] It can be understood that the terms "first", "second" and the like used in the present application can be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. For example, without departing from the scope of the present application, the first resistor can be referred to as the second resistor, and similarly, the second resistor can be referred to as the first resistor. The first resistor and the second resistor are both resistors, but they are not the same resistor.

[0038] It can be understood that "connection" in the following embodiments, if the circuits, modules, units and the like connected to each other have the transmission of electrical signals or data, should be understood as "electrical connection", "communication connection" and the like.

[0039] As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including", or the like, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof. Also, the term "and / or" includes any and all combinations of associated items.

[0040] With the popularity of power equipment, the demand for power supply of various chargeable equipment is increasing. The existing bidirectional power supply or three-phase charging module widely uses three-phase totem pole bridgeless PFC to improve the power supply efficiency.

[0041] The totem pole structure is a circuit topology composed of two switching tubes vertically stacked, similar to the shape of a totem pole. This structure can achieve efficient power conversion. The traditional PFC circuit usually uses a bridge rectifier, while the three-phase bridgeless PFC omits this part and directly uses six switching tubes to control the three-phase input current, simplifying the circuit structure. The three-phase totem pole bridgeless PFC has a high power factor, can reduce grid harmonic pollution, reduce line loss, simplify circuit structure, and is suitable for medium and high power application occasions.

[0042] However, when the traditional bidirectional power supply or three-phase charging module is applied to the three-phase totem pole bridgeless PFC, the inductor current will interfere through the diodes of the pre-charge circuit due to impedance problems, causing high-frequency current to flow through the diodes, which may damage the diodes and resistors of the pre-charge circuit. The traditional solution adds multiple relays and relay control circuits to the pre-charge circuit to control the current input of the pre-charge circuit to avoid high-frequency current, which has high design cost and large equipment size.

[0043] Based on this, the utility model provides a bidirectional power supply pre-charge circuit and equipment to solve the above problems.

[0044] In one exemplary embodiment, as shown in Figure 1 A bidirectional power supply pre-charge circuit is provided, including a relay module 100, an input switching control module 200, a power module 300, and a pre-charge module 400.

[0045] The relay module 100 includes a first relay K1 corresponding to phase a, a second relay K2 corresponding to phase b, and a third relay K3 corresponding to phase c. The relay module 100 is connected to the input switching control module 200, the power module 300, and the pre-charge module 400, respectively.

[0046] The input switching control module 200 is used for controlling the opening and closing of the first relay K1, the second relay K2 and the third relay K3, so as to realize the switching between the pre-charging module 400 and the power module 300.

[0047] Optionally, the relay module 100 is composed of the first relay K1, the second relay K2 and the third relay K3, corresponding to the a-phase input, the b-phase input and the c-phase input of the three-phase alternating current respectively, and is used for receiving the control signal of the input switching control module 200, transmitting the input current of each phase to the power module 300 or the pre-charging module 400, realizing the flexible control of the current of the power module 300 or the pre-charging module 400, and solving the high-frequency current crosstalk of the inductor.

[0048] The input switching control module 200 is used for controlling the opening and closing of the first relay K1, the second relay K2 and the third relay K3, so as to realize the switching between the pre-charging module 400 and the power module 300.

[0049] The power module 300 is used for chopping modulation and power transmission, and realizes AC (alternating current)-DC (direct current) conversion.

[0050] The pre-charging module 400 is used for protecting the power module 300 and constitutes a pre-charging loop of the bidirectional power pre-charging circuit, so as to realize the wake-up and communication functions of the circuit.

[0051] The bidirectional power pre-charging circuit realizes the switching between the pre-charging module 400 and the power module 300 by using only one relay in each phase, can flexibly control the pre-charging module, solves the high-frequency current crosstalk problem, does not need to add a relay and a relay control circuit in the pre-charging module 400, reduces the design cost and the equipment size.

[0052] The following some embodiments specifically describe the process of realizing the switching between the power module and the pre-charging module.

[0053] In an exemplary embodiment, the input switching control module 200 is further used for, in the case of receiving a standby instruction, controlling the normally closed contact of the first relay K1, the second relay K2 and the third relay K3 to be closed and the normally open contact to be opened, so as to switch from the power module 300 to the pre-charging module 400.

[0054] Exemplarily, when the input switching control module 200 receives a standby instruction, the normally closed contacts of the first relay K1, the second relay K2 and the third relay K3 are controlled to be closed, the normally open contacts are controlled to be opened, the input of the power module 300 in the circuit is disconnected, and the three-phase alternating current input is switched to the pre-charge module 400. In addition, when the circuit is in a standby state, the normally closed contacts of the first relay K1, the second relay K2 and the third relay K3 remain in a closed state, the diodes in the pre-charge module 400 charge the output bus, and the power module 300 does not work, so as to realize the wake-up and communication functions of the circuit.

[0055] In the embodiment, the normally closed contacts of the relays are controlled by the input switching control module 200 to form a pre-charge circuit, so as to ensure smooth start of the circuit, reduce voltage and current fluctuations during start, prolong the service life of the circuit, and realize the wake-up and communication functions of the circuit.

[0056] In an exemplary embodiment, the input switching control module 200 is further configured to, in the case of receiving a power transmission instruction, control the normally closed contacts of the first relay K1, the second relay K2 and the third relay K3 to be opened, and control the normally open contacts to be closed, so as to switch from the pre-charge module 400 to the power module 300.

[0057] Exemplarily, when the circuit system needs to perform PFC power transmission, the input switching control module 200 receives a power transmission instruction, controls the normally closed contacts of the first relay K1, the second relay K2 and the third relay K3 to be opened, and controls the normally open contacts to be closed, so that the input of the pre-charge module 400 is disconnected, and the power module 300 starts to work. The power module 300 constitutes a three-phase totem-pole bridgeless PFC circuit, performs chopper modulation, and completes the power transmission work.

[0058] In the embodiment, the normally closed contacts of the relays are controlled by the input switching control module 200 to form a power circuit, and the power circuit adopts a three-phase totem-pole bridgeless PFC to complete power transmission, so as to improve the AC-DC conversion efficiency. Meanwhile, the switching between the power module 300 and the pre-charge module 400 can be realized by using only one relay in each phase, so as to reduce the cost and the size of the circuit equipment.

[0059] The following embodiments specifically introduce the structures of the modules of the utility model.

[0060] In an exemplary embodiment, as shown in Figure 2 The power module 300 includes a first power unit 310, a second power unit 320 and a third power unit 330.

[0061] As shown in Figure 3 The pre-charge module 400 includes a first pre-charge unit 410, a second pre-charge unit 420 and a third pre-charge unit 430.

[0062] The first pins of the first relay K1, the second relay K2 and the third relay K3 are grounded respectively.

[0063] The second pins of the first relay K1, the second relay K2 and the third relay K3 are connected with the first power unit 310, the second power unit 320 and the third power unit 330 respectively.

[0064] The third pins of the first relay K1, the second relay K2 and the third relay K3 are connected with the first pre-charge unit 410, the second pre-charge unit 420 and the third pre-charge unit 430 respectively.

[0065] The fourth pins of the first relay K1, the second relay K2 and the third relay K3 are connected with the a-phase control signal Ua, the b-phase control signal Ub and the c-phase control signal Uc of the input switching control module 200 respectively.

[0066] The fifth pins of the first relay K1, the second relay K2 and the third relay K3 are connected with the a-phase, the b-phase and the c-phase of the three-phase alternating current respectively.

[0067] Exemplarily, in combination with Figure 4 The bidirectional power pre-charge circuit is illustrated. Figure 4 The first pins (the negative poles of the relay coils) of the relays are grounded; the second pins (the normally open contacts) of the relays are connected with the PFC power units, and the three-phase alternating current is transmitted to the PFC power units; the third pins (the normally closed contacts) of the relays are connected with the PFC pre-charge units, and the three-phase alternating current is transmitted to the PFC pre-charge units, and the input voltages are represented by UsaIN, UsbIN and UscIN respectively; the fourth pins (the positive poles of the relay coils) of the relays are connected with the control signals Ua, Ub and Uc of the input switching control module 200, and are used for controlling the opening and closing of the normally closed contacts and the normally open contacts of the relays; the fifth pins (the common contacts) of the relays are connected with the three-phase alternating current, and the input of each phase is represented by Usa, Usb and Usc, and the basic power supply of the circuit is provided.

[0068] The bidirectional power pre-charge circuit has wide application, can perform the pre-charge function after being connected with the commercial power, and has accurate and efficient circuit switching control, only one relay is used for each phase, the circuit design cost is greatly reduced, and the size of the circuit equipment is reduced.

[0069] In one exemplary embodiment, please refer to Figure 4The first power unit 310 includes a first inductor L1, a first switch Q1, and a fourth switch Q4; the first end of the first inductor L1 is connected to the second pin of the first relay K1, and the second end of the first inductor L1 is connected to the first end of the first switch Q1 and the first end of the fourth switch Q4, respectively.

[0070] The second power unit 320 includes a second inductor L2, a second switch Q2, and a fifth switch Q5; the first end of the second inductor L2 is connected to the second pin of the second relay K2, and the second end of the second inductor L2 is connected to the first ends of the second switch Q1 and the fifth switch Q5, respectively.

[0071] The third power unit 330 includes a third inductor L3, a third switch Q3, and a sixth switch Q6; the first end of the third inductor L3 is connected to the second pin of the third relay K3, and the second end of the third inductor L3 is connected to the first ends of the third switch Q3 and the sixth switch Q6, respectively.

[0072] In one exemplary embodiment, each switch is a metal-oxide-semiconductor field-effect transistor.

[0073] For example, each switch is a power MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), forming a three-phase totem pole bridgeless PFC circuit.

[0074] In this embodiment, the switching transistors form a three-phase totem pole bridgeless PFC, which can improve the power factor of the circuit, reduce grid harmonic pollution, reduce line loss, and simplify the circuit structure.

[0075] In an exemplary embodiment, the first precharge unit 410 includes a first resistor R1, a first diode D1, and a fourth diode D4; the first end of the first resistor R1 is connected to the third pin of the first relay K1, and the second end of the first resistor R1 is connected to the anode of the first diode D1 and the cathode of the fourth diode D2, respectively.

[0076] The second precharge unit 420 includes a second resistor R2, a second diode D2, and a fifth diode D5; the first end of the second resistor R2 is connected to the third pin of the second relay K2, and the second end of the second resistor R2 is connected to the anode of the second diode D2 and the cathode of the fifth diode D5, respectively.

[0077] The third precharge unit 430 includes a third resistor R3, a third diode D3, and a sixth diode D6; the first end of the third resistor R3 is connected to the third pin of the third relay K3, and the second end of the third resistor R3 is connected to the anode of the third diode D3 and the cathode of the sixth diode D6, respectively.

[0078] In the above embodiment, each diode constitutes a three-phase totem-pole bridgeless PFC, realizes high-efficiency and reliable power factor correction, and improves stability of the pre-charge circuit.

[0079] In one example embodiment, referring to Figure 4 The circuit further comprises an output module 500.

[0080] The output module 500 is connected with the power module 300 and the pre-charge module 400 respectively, and is configured to output a direct current.

[0081] In an example, the output module 500 is connected with the second end of each switch tube, and is connected with the cathodes of the first diode D1, the second diode D2 and the third diode D3, and is connected with the anodes of the fourth diode D4, the fifth diode D5 and the sixth diode D6.

[0082] In one example embodiment, referring to Figure 4 The output module 500 comprises an output capacitor C and an output resistor R, and the output capacitor C is connected with the output resistor R in parallel.

[0083] In the above embodiment, the output capacitor C is connected with the output resistor R in parallel, which can stabilize the output voltage, filter the output voltage, improve the performance of the circuit, and improve the stability and reliability of the circuit system.

[0084] In one example embodiment, the utility model further provides a bidirectional power pre-charge device, which comprises the bidirectional power pre-charge circuit in any of the above embodiments.

[0085] It can be understood that the bidirectional power pre-charge circuit can also adopt other forms, and is not limited to the forms mentioned in the above embodiments, as long as it can achieve the function of solving high-frequency current crosstalk.

[0086] In addition, although flip-flops triggered along are used in the above embodiments, flip-flops triggered by levels can be used alternatively.

[0087] In the description of the present specification, the description of the terms "some embodiments", "other embodiments", "ideal embodiments", and the like means that the specific features, structures, materials or characteristics described in combination with the embodiments or examples are contained in at least one embodiment or example of the utility model. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0088] Each technical feature of the above embodiments can be combined arbitrarily, and in order to make the description concise, each technical feature in the above embodiments is not described in all possible combinations, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present specification.

[0089] The above embodiments only express several implementation manners of the utility model, the description is more specific and detailed, but can not therefore be understood as the limitation of the utility model patent range. It should be pointed out that for ordinary skilled person in the art, without departing from the utility model concept, several modifications and improvements can be made, which belong to the protection range of the utility model. Therefore, the protection range of the utility model patent should be subject to the appended claims.

Claims

1. A bidirectional power pre-charge circuit, comprising: The application relates to a relay module, an input switching control module, a power module and a pre-charging module. The relay module comprises a first relay corresponding to phase a, a second relay corresponding to phase b and a third relay corresponding to phase c, and is connected with the input switching control module, the power module and the pre-charging module respectively. The input switching control module is used for controlling the opening and closing of the first relay, the second relay and the third relay, so as to realize the switching between the pre-charging module and the power module. The input switching control module is further used for controlling the closing of the normally closed contact and the opening of the normally open contact of the first relay, the second relay and the third relay, so as to switch from the power module to the pre-charging module when a standby instruction is received.

2. The bidirectional power precharge circuit of claim 1, wherein, The input switching control module is further used for controlling the opening of the normally closed contact and the closing of the normally open contact of the first relay, the second relay and the third relay, so as to switch from the pre-charging module to the power module when a power transmission instruction is received.

3. The bidirectional power precharge circuit of claim 1, wherein, The power module comprises a first power unit, a second power unit and a third power unit; and the pre-charging module comprises a first pre-charging unit, a second pre-charging unit and a third pre-charging unit.

4. The bidirectional power precharge circuit of claim 1, wherein, The first pins of the first relay, the second relay and the third relay are grounded respectively. The second pins of the first relay, the second relay and the third relay are connected with the first power unit, the second power unit and the third power unit respectively. The third pins of the first relay, the second relay and the third relay are connected with the first pre-charging unit, the second pre-charging unit and the third pre-charging unit respectively. The fourth pins of the first relay, the second relay and the third relay are connected with the phase a control signal, the phase b control signal and the phase c control signal of the input switching control module respectively. The fifth pins of the first relay, the second relay and the third relay are connected with the phase a, the phase b and the phase c of the three-phase alternating current respectively. The first power unit comprises a first inductor, a first switch tube and a fourth switch tube; the first end of the first inductor is connected with the second pin of the first relay, and the second end of the first inductor is connected with the first end of the first switch tube and the fourth switch tube respectively.

5. The bidirectional power precharge circuit of claim 4, wherein, The second power unit comprises a second inductor, a second switch tube and a fifth switch tube; the first end of the second inductor is connected with the second pin of the second relay, and the second end of the second inductor is connected with the first end of the second switch tube and the fifth switch tube respectively. The third power unit comprises a third inductor, a third switch tube and a sixth switch tube; the first end of the third inductor is connected with the second pin of the third relay, and the second end of the third inductor is connected with the first end of the third switch tube and the sixth switch tube respectively. Each switch tube is a metal oxide semiconductor field effect transistor.

6. The bidirectional power precharge circuit of claim 5, wherein, ​ 7. The bidirectional power precharge circuit of claim 4, wherein, The first pre-charging unit comprises a first resistor, a first diode and a fourth diode; a first end of the first resistor is connected with a third pin of the first relay, and a second end of the first resistor is connected with an anode of the first diode and a cathode of the fourth diode respectively; The second pre-charging unit comprises a second resistor, a second diode and a fifth diode; a first end of the second resistor is connected with a third pin of the second relay, and a second end of the second resistor is connected with an anode of the second diode and a cathode of the fifth diode respectively; The third pre-charging unit comprises a third resistor, a third diode and a sixth diode; a first end of the third resistor is connected with a third pin of the third relay, and a second end of the third resistor is connected with an anode of the third diode and a cathode of the sixth diode respectively.

8. The bidirectional power precharge circuit of claim 1, wherein, The circuit further comprises: An output module connected with the power module and the pre-charging module respectively, for outputting direct current.

9. The bidirectional power precharge circuit of claim 8, wherein, The output module comprises an output capacitor and an output resistor, and the output capacitor is connected with the output resistor in parallel.

10. A bidirectional power precharge device, comprising: A bidirectional power pre-charging circuit comprising any one of claims 1-9.

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