A low-cost, functionally safe dual-motor low-voltage power supply circuit

Abstract

This utility model provides a low-cost, functionally safe dual-motor low-voltage power supply circuit, including an input voltage terminal, a flyback isolated power supply module, a feedback control circuit, a first main output circuit, and a second main output circuit. The flyback isolated power supply module includes a flyback transformer, a flyback control chip, and a power switch. The flyback transformer includes a first primary winding, a feedback secondary winding, and a main output secondary winding. One end of the first primary winding is connected to the input voltage terminal, and the other end is connected to the power switch. The feedback secondary winding is connected to the feedback control circuit, which is connected to the flyback control chip. The flyback control chip is connected to the power switch. The main output secondary winding is connected to the first main output circuit and the second main output circuit. The first main output circuit is connected to and supplies power to a non-isolated functional module, and the second main output circuit is connected to and supplies power to a power module on the IGBT three-bridge.

Description

Technical Field

[0001] This utility model relates to the field of motor power supply circuits, and in particular to a low-cost dual-motor low-voltage power supply circuit with functional safety. Background Technology

[0002] Traditional dual-motor power supply solutions typically employ multiple independently isolated power modules to ensure functional safety, but this approach is extremely costly, bulky, and requires limited board space. In scenarios requiring multiple isolated power supplies, if all isolated power supplies use flyback outputs, traditional solutions are difficult to implement for the following reasons: (1) Using a frame transformer results in too many windings, making the transformer bulky and requiring a large amount of space, and also results in too many output pins, making traditional frame transformers difficult to implement; (2) Using a planar transformer increases the number of PCB layers required due to the large number of outputs, significantly increasing costs. Utility Model Content

[0003] To overcome the above-mentioned technical defects, the purpose of this utility model is to provide a low-cost dual-motor low-voltage power supply circuit with functional safety. It sets up an isolated drive power supply, uses only one flyback power supply and two external transformers to achieve one main output plus six upper bridge power supplies, which greatly reduces costs and has functional safety.

[0004] This utility model discloses a low-cost, functionally safe dual-motor low-voltage power supply circuit, comprising: Input voltage terminal, flyback isolation power supply module, feedback control circuit, first main output circuit and second main output circuit; The flyback isolated power supply module includes a flyback transformer, a flyback control chip, and a power switch. The flyback transformer includes a first primary winding, a feedback secondary winding, and a main output secondary winding. One end of the first primary winding is connected to the input voltage terminal, and the other end of the first primary winding is connected to the power switch. The feedback secondary winding is connected to a feedback control circuit, which is connected to the flyback control chip. The flyback control chip is connected to the power switch. The main output secondary winding is connected to the first main output circuit and the second main output circuit. The first main output circuit is connected to and supplies power to the non-isolated functional module, and the second main output circuit is connected to and supplies power to the power module of the IGBT three-bridge.

[0005] Preferably, one end of the main output secondary winding is connected to the input terminal of the first main output circuit and the primary side of the second main output circuit, and the other end of the main output secondary winding is connected to the common ground of the first main output circuit and the second main output circuit.

[0006] Preferably, the second main output circuit includes two 1-to-3 transformers, each 1-to-3 transformer including a second primary winding and three second secondary windings, and the six output terminals of the three second secondary windings are connected to the power module.

[0007] Preferably, one end of the second secondary winding is connected to the anode of the second rectifier diode, and the other end of the second secondary winding is grounded.

[0008] Preferably, the first main output circuit includes a first rectifier diode and a P15V voltage output terminal. The anode of the first rectifier diode is connected to one end of the main output secondary winding, and the cathode of the first rectifier diode is connected to the P15V voltage output terminal.

[0009] Preferably, the feedback control circuit includes a third rectifier diode and a voltage divider resistor group. The anode of the third rectifier diode is connected to one end of the feedback secondary winding, and the cathode of the third rectifier diode is connected to the voltage divider resistor group. The voltage divider point of the voltage divider resistor group leads out the FB control signal, and the voltage divider point is connected to the flyback control chip. The other end of the feedback secondary winding is grounded.

[0010] Preferably, the voltage divider resistor group includes two voltage divider resistors, and the voltage divider point is set between the two voltage divider resistors.

[0011] Preferably, the Driver pin of the flyback control chip is connected to the gate of the power switch.

[0012] Preferably, the flyback isolated power supply module further includes a current sampling resistor, with the current sampling pin of the flyback control chip connected to one end of the current sampling resistor and the other end of the current sampling resistor grounded.

[0013] Preferably, the power switch is connected in series between the first primary winding and ground.

[0014] Compared with existing technologies, the above technical solution has the following advantages: 1. In one embodiment of this utility model, the magnetic reset of the one-to-three transformer is achieved through a flyback isolation power supply module, thereby eliminating the magnetic reset winding and reducing the board area; 2. In one embodiment of this utility model, the one-to-three transformer uses the PWM wave generated by the main output secondary winding to transfer energy to the secondary side of the one-to-three transformer. Compared with the traditional forward power supply, this method eliminates the need for MOSFETs and corresponding drive circuits, reducing costs and PCB complexity. 3. One embodiment of this utility model effectively solves the problem of multi-output with functional safety in dual-motor systems. It only requires one flyback power supply and two transformers to obtain one main output plus six upper bridge power supplies. The solution has a simple structure, low cost, and is more suitable for vehicle applications. Attached Figure Description

[0015] Figure 1 This invention discloses a dual-motor low-voltage power supply circuit as one embodiment of the present invention.

[0016] Figure reference numerals: 101-Input voltage terminal, 201-Flyback control chip, 202-Current sampling resistor, 301-First rectifier diode, 401-One-to-three transformer. Detailed Implementation

[0017] The advantages of this utility model are further illustrated below with reference to the accompanying drawings and specific embodiments.

[0018] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0019] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0020] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0021] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0022] In the description of this utility model, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0023] In the following description, the use of suffixes such as "module," "part," or "unit" to denote elements is solely for the purpose of illustrating this invention and has no specific meaning in itself. Therefore, "module" and "part" can be used interchangeably.

[0024] One embodiment of this utility model discloses a low-cost, functionally safe dual-motor low-voltage power supply circuit, comprising: Input voltage terminal 101, flyback isolation power supply module, feedback control circuit, first main output circuit and second main output circuit; The flyback isolated power supply module includes a flyback transformer, a flyback control chip 102, and a power switch. The flyback transformer includes a first primary winding, a feedback secondary winding, and a main output secondary winding. One end of the first primary winding is connected to the input voltage terminal 101, and the other end is connected to the power switch. The feedback secondary winding is connected to a feedback control circuit, which is connected to the flyback control chip 102. The flyback control chip 102 is connected to the power switch. The main output secondary winding is connected to the first main output circuit and the second main output circuit. The first main output circuit is connected to and supplies power to the non-isolated functional module, and the second main output circuit is connected to and supplies power to the power module of the IGBT upper three-bridge.

[0025] Specifically, in this embodiment, the input voltage at input voltage terminal 101 is processed by the flyback isolation power supply module to generate one feedback output and two main outputs. The flyback isolation power supply module drives the power switching transistor to control the energy storage / release on the primary side of the flyback transformer. At the same time, it receives feedback signals and completes functions such as voltage regulation and overcurrent protection. The flyback transformer transfers energy to the two main output circuits through the secondary winding of the main output. The feedback control circuit sends the signal back to the flyback isolation power supply module to form a voltage regulation closed loop. The flyback isolation power supply module is the only active switching stage of this power supply circuit device, which converts and isolates the battery voltage to generate the main output.

[0026] Preferably, the input voltage terminal 101 is equipped with a KL30 power line, which is directly connected to one end of the first primary winding of the flyback transformer to provide input energy for the entire flyback isolation power supply module. Preferably, in the flyback isolated power supply module, the Driver pin of the flyback control chip 102 is connected to the gate of the power switch transistor to drive the power switch transistor to turn on and off; the flyback isolated power supply module also includes a current sampling resistor 202, the current sampling pin of the flyback control chip 102 is connected to one end of the current sampling resistor 202 to collect the primary current and realize overcurrent protection, and the other end of the current sampling resistor 202 is grounded; the power switch transistor is connected in series between the first primary winding and ground, preferably a MOSFET; In the flyback isolated power supply module, the main output secondary winding is the energy output winding of the flyback isolated power supply module. One end of the main output secondary winding is connected to the input terminal of the first main output circuit and the primary side of the second main output circuit to supply power to the two main output circuits. The other end of the main output secondary winding is connected to the common ground of the first main output circuit and the second main output circuit.

[0027] Preferably, the first main output circuit includes a first rectifier diode 301 and a P15V voltage output terminal. The anode of the first rectifier diode 301 is connected to one end of the main output secondary winding, and the cathode of the first rectifier diode is connected to the P15V voltage output terminal. The stable DC voltage obtained after the P15V voltage is rectified and filtered by the first rectifier diode is used to power other functional modules, usually other non-isolated control circuits. The second main output circuit includes two 1-to-3 transformers 401. Each 1-to-3 transformer 401 includes one second primary winding and three second secondary windings. That is, each 1-to-3 transformer 401 has one second primary winding and three independent and electrically isolated second secondary windings. Thus, the two 1-to-3 transformers 401 generate two second primary windings and six second secondary windings. The six second secondary windings have six outputs, namely P22V_U1, P22V_V1, P22V_W1, P22V_U2, P22V_V2, and P22V_W2. The six output terminals of the three secondary windings are connected to the power module; one end of the secondary winding is connected to the anode of the second rectifier diode, and the other end of the secondary winding is grounded; when a PWM voltage pulse is applied to one of the primary windings, the energy is coupled to the three secondary windings simultaneously in forward mode. After being rectified and filtered by their respective second rectifier diodes, three mutually isolated DC voltages with the same ground as the primary winding are generated. The DC voltage is preferably adapted to the dual-motor IGBT three-phase bridge power module. Specifically, the 1-to-3 transformer 401 is not a complete switching power supply transformer. It lacks its own switching transistors, independent drive circuits, and large input capacitors, relying entirely on the PWM waveform provided by the preceding flyback isolation power supply module. Its function is equivalent to an energy distributor and isolator operating in forward mode. The primary winding of the 1-to-3 transformer 401 is directly connected in parallel to the main output secondary winding of the flyback transformer. When the power switching transistor of the flyback isolation power supply module is turned off, causing the flyback transformer to undergo magnetic reset, a voltage will be generated across the main output secondary winding of the flyback transformer. A reverse voltage is applied to the second primary winding of the three-way transformer 401, automatically completing the magnetic reset of the three-way transformer 401. In this way, the magnetic reset of the three-way transformer 401 is achieved through the flyback isolation power supply module, eliminating the need for the magnetic reset winding required by the three-way transformer 401 itself and reducing the board area. In addition, the primary PWM wave of the three-way transformer 401 is directly generated by the switching action of the front-end flyback isolation power supply module. The entire system has only one active switching transistor, namely the power switching transistor of the flyback isolation power supply module, which greatly reduces the cost and complexity.

[0028] Preferably, the feedback control circuit includes a third rectifier diode and a voltage divider resistor group. The anode of the third rectifier diode is connected to one end of the feedback secondary winding, and the cathode of the third rectifier diode is connected to the voltage divider resistor group. The voltage divider point of the voltage divider resistor group leads out the FB control signal, and the voltage divider point is connected to the flyback control chip 102. The signal after voltage division is fed back to the flyback control chip 102 through the FB pin to realize the voltage regulation of the output voltage. The other end of the feedback secondary winding is grounded. The voltage divider resistor group includes two voltage divider resistors, and a voltage divider point is set between the two voltage divider resistors.

[0029] It should be noted that the embodiments of this utility model have better implementability and are not intended to limit this utility model in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of this utility model without departing from the content of the technical solution of this utility model shall still fall within the scope of the technical solution of this utility model.

Claims

1. A low-cost, functionally safe, dual-motor low-voltage power supply circuit, characterized in that, include: Input voltage terminal, flyback isolation power supply module, feedback control circuit, first main output circuit and second main output circuit; The flyback isolated power supply module includes a flyback transformer, a flyback control chip, and a power switch. The flyback transformer includes a first primary winding, a feedback secondary winding, and a main output secondary winding. One end of the first primary winding is connected to the input voltage terminal, and the other end of the first primary winding is connected to the power switch. The feedback secondary winding is connected to a feedback control circuit, which is connected to the flyback control chip. The flyback control chip is connected to the power switch. The main output secondary winding is connected to the first main output circuit and the second main output circuit. The first main output circuit is connected to and supplies power to the non-isolated functional module, and the second main output circuit is connected to and supplies power to the power module of the IGBT three-bridge.

2. The low-cost, functionally safe dual-motor low-voltage power supply circuit as described in claim 1, characterized in that, One end of the main output secondary winding is connected to the input terminal of the first main output circuit and the primary side of the second main output circuit, and the other end of the main output secondary winding is connected to the common ground of the first main output circuit and the second main output circuit.

3. The low-cost, functionally safe dual-motor low-voltage power supply circuit as described in claim 1, characterized in that, The second main output circuit includes two 1-to-3 transformers. Each 1-to-3 transformer includes a second primary winding and three second secondary windings. The six output terminals of the three second secondary windings are connected to the power module.

4. A low-cost, functionally safe dual-motor low-voltage power supply circuit as described in claim 3, characterized in that, One end of the second secondary winding is connected to the anode of the second rectifier diode, and the other end of the second secondary winding is grounded.

5. A low-cost, functionally safe dual-motor low-voltage power supply circuit as described in claim 1, characterized in that, The first main output circuit includes a first rectifier diode and a P15V voltage output terminal. The anode of the first rectifier diode is connected to one end of the main output secondary winding, and the cathode of the first rectifier diode is connected to the P15V voltage output terminal.

6. A low-cost, functionally safe dual-motor low-voltage power supply circuit as described in claim 1, characterized in that, The feedback control circuit includes a third rectifier diode and a voltage divider resistor group. The anode of the third rectifier diode is connected to one end of the feedback secondary winding, and the cathode of the third rectifier diode is connected to the voltage divider resistor group. The voltage divider point of the voltage divider resistor group leads out the FB control signal, and the voltage divider point is connected to the flyback control chip. The other end of the feedback secondary winding is grounded.

7. A low-cost, functionally safe dual-motor low-voltage power supply circuit as described in claim 6, characterized in that, The voltage divider resistor group includes two voltage divider resistors, and the voltage divider point is set between the two voltage divider resistors.

8. A low-cost, functionally safe dual-motor low-voltage power supply circuit as described in claim 1, characterized in that, The Driver pin of the flyback control chip is connected to the gate of the power switch.

9. A low-cost, functionally safe dual-motor low-voltage power supply circuit as described in claim 8, characterized in that, The flyback isolated power supply module also includes a current sampling resistor. The current sampling pin of the flyback control chip is connected to one end of the current sampling resistor, and the other end of the current sampling resistor is grounded.

10. A low-cost, functionally safe dual-motor low-voltage power supply circuit as described in claim 1, characterized in that, The power switch is connected in series between the first primary winding and ground.

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