Power supply circuit device and controller using the same

Abstract

The present invention relates to a power supply circuit device and a controller using the same. The power supply circuit device includes a PCB board, on which a switching power supply circuit is provided. The switching power supply circuit includes a switching module, a switching transformer, a rectification module, and a filtering module. The switching module is provided with a spike absorption circuit. The switching module is powered by a DC bus power supply. The traces connecting the positive pole of the DC bus power supply, the spike absorption circuit, the first winding of the switching transformer, the input pole of the switching transistor of the switching module, and the output pole of the switching transistor of the switching module to the negative pole of the DC bus power supply form a bus current loop. The area of the bus current loop is 100 square millimeters to 200 square millimeters, and the trace width is 0.7 millimeters to 2.4 millimeters. In this way, the interference signal of the emitted electromagnetic field of the current loop can be effectively reduced, thereby effectively reducing the interference to the surrounding circuits, especially the weak-current MCU control circuit. In this way, the anti-interference ability of the entire control circuit is improved, and the working reliability of the entire control circuit is enhanced.

Description

Technical Field

[0001] The present invention relates to a power supply circuit device and a controller using the same, and belongs to the technical field of controller applications. Background Art

[0002] In current electronic appliances and home appliance products, switching power supplies are very commonly used. Due to the high frequency of switching power supplies, the high-frequency switching actions of power switching devices are one of the main reasons for electromagnetic interference (EMI) generated by electronic systems. When a switching power supply is working, the voltage and current waveforms inside it rise and fall within a very short time. Therefore, the switching power supply itself is a noise source. Whether the PCB wiring design of the circuit board of the switching power supply is reasonable will critically affect the interference of the noise propagation to other modules in the circuit, such as the MCU control part and the drive part. Currently, in some applications, not much attention is paid to the PCB wiring of the switching power supply, but rather to the wiring of other circuit modules, which leads to the problem of unstable operation of the entire circuit board. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to solve the problem that in the control circuit board of existing home appliance products, the unreasonable PCB wiring of the switching power supply leads to the unstable operation of the entire control circuit board.

[0004] Specifically, the present invention discloses a power supply circuit device, including a PCB board. A switching power supply circuit is provided on the PCB board. The switching power supply circuit includes a switching module, a switching transformer, a rectification module, and a filtering module. The switching module is connected to the input winding of the switching transformer. The rectification module is connected to the output winding of the switching transformer. The filtering module is connected to the rectification module. The switching module is provided with a spike absorption circuit. The switching module is powered by a DC bus power supply. The trace connecting the positive pole of the DC bus power supply, the spike absorption circuit, the first winding of the switching transformer, the input pole of the switching transistor of the switching module, and the output pole of the switching transistor of the switching module to the negative pole of the DC bus power supply forms a bus current loop. The area of the bus current loop is 100 square millimeters to 200 square millimeters, and the trace width is 0.7 millimeters to 2.4 millimeters.

[0005] Optionally, the spike absorption circuit includes a first capacitor, a second capacitor, a first resistor, and a first diode. The first capacitor is connected in parallel between the positive and negative terminals of the DC bus power input. One end of the first resistor is connected to the positive terminal of the DC bus power, the other end of the first resistor is connected to the cathode of the first diode, and the anode of the first diode is connected to the input terminal of the switching transistor of the switching module. The second capacitor is connected in parallel with the first resistor. The trace connecting one end of the first resistor, the input winding of the switching transformer, the anode of the first diode, and the input terminal of the switching transistor of the switching module forms a spike absorption current loop, and the area of the spike absorption current loop is 20 square millimeters to 60 square millimeters.

[0006] Optionally, the positive and negative output power traces connecting the filtering module to the powered electrical load are arranged in parallel, and the distance between the positive and negative output power traces is 0.254 millimeters to 0.35 millimeters.

[0007] Optionally, the PCB board is a double-sided board. The positive and negative output power traces are respectively arranged on two sides of the PCB board. One end of the negative power trace is connected to the negative terminal of the filtering module, and the other end is connected to the ground terminal of the output winding of the switching transformer.

[0008] Optionally, there are multiple rectifying modules and filtering modules. The widths of the positive and negative power traces connecting the multiple rectifying modules and filtering modules are consistent with the over-current magnitudes of the corresponding rectifying modules and filtering modules.

[0009] Optionally, the rectifying module includes a second diode connected in series to the positive output power trace, and the second diode is arranged close to the output terminal of the second winding of the switching transformer.

[0010] Optionally, the filtering module includes a third electrolytic capacitor. The third electrolytic capacitor is arranged close to the second diode and is connected in parallel between the positive and negative output power traces. The second diode and the third electrolytic capacitor are arranged according to the following rule: the connection direction of the two pins of the second diode is not parallel to the connection direction of the two pins of the third electrolytic capacitor.

[0011] Optionally, the connection direction of the two pins of the second diode is perpendicular to the connection direction of the two pins of the third electrolytic capacitor.

[0012] The present invention also discloses a controller. The controller is provided with the above-mentioned power circuit device, and also provided with an MCU control circuit and a motor drive module. The motor drive module includes an integrated semiconductor circuit and a sampling resistor for sampling three-phase currents output by the semiconductor circuit. Among them, the first bus negative electrode trace for supplying power to the semiconductor circuit, the second bus negative electrode trace for supplying power to the switching power supply, and the third bus negative electrode trace connecting the MCU control circuit are commonly connected to a grounding bonding area close to the connection of the sampling resistor.

[0013] Optionally, the width of the negative electrode trace of the output power supply for supplying power to the semiconductor circuit connecting the power circuit device is smaller than that of the first bus ground wire and the second bus ground wire, and the negative electrode trace is far away from the first bus ground wire and the second bus ground wire, and the negative electrode trace is connected to the grounding bonding area.

[0014] The power circuit device of the present invention includes a PCB board. A switching power supply circuit is provided on the PCB board. The switching power supply circuit includes a switching module, a switching transformer, a rectification module, and a filtering module. The switching module is connected to the input winding of the switching transformer, the rectification module is connected to the output winding of the switching transformer, and the filtering module is connected to the rectification module. The switching module is provided with a spike absorption circuit. The switching module is powered by a DC bus power supply. The traces connecting the positive pole of the DC bus power supply, the spike absorption circuit, the first winding of the switching transformer, the input pole of the switching tube of the switching module, and the output pole of the switching tube of the switching module to the negative pole of the DC bus power supply form a bus current loop. The area of the bus current loop is 100 square millimeters to 200 square millimeters, and the trace width is 0.7 millimeters to 2.4 millimeters. In this way, the interference signal of the emitted electromagnetic field of the current loop can be effectively reduced, thereby effectively reducing the interference to the surrounding circuits, especially the MCU control circuit operating at low voltage. In this way, the anti-interference ability of the entire control circuit is improved, and thus the working reliability of the entire control circuit is enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is the PCB wiring and silk screen diagram of the controller according to the embodiment of the present invention;

[0016] Figure 2 It is Figure 1 The enlarged view of the power circuit part corresponding to A1 in

[0017] Figure 3 It is Figure 1 Another enlarged view of the power circuit part corresponding to A1 in

[0018] Figure 4 It is Figure 1 The front wiring and front silk screen diagram of the PCB in

[0019] Figure 5 It is Figure 4The enlarged view of the power supply circuit part corresponding to A2 in

[0020] Figure 6 is Figure 5 the enlarged view corresponding to C in

[0021] Figure 7 is Figure 1 the backside wiring and front side silk screen diagram of the PCB in

[0022] Figure 8 is Figure 7 the enlarged view corresponding to A3 in

[0023] Figure 9 the circuit schematic diagram of the power supply circuit device according to the embodiment of the present invention;

[0024] Figure 10 the circuit schematic diagrams of the MCU control circuit and the inverter module in the controller according to the embodiment of the present invention. Detailed implementation manners

[0025] It should be noted that, without conflict in structure or function, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to examples.

[0026] The present invention first proposes a power supply circuit device, as Figures 1 to 9 shown, which includes a PCB board. A switching power supply circuit is provided on the PCB board. Some electronic components are installed on the PCB board. There are traces formed by copper foils on the PCB board. A switching power supply circuit is formed through the traces and the electronic components to convert the input alternating current into an output low-voltage direct current. The switching power supply circuit can output multiple paths of low-voltage direct current, such as +5V, +12V, and +15V, etc., to supply power to different electrical loads. As Figure 9 shown, the switching power supply circuit includes a switching module 10, a switching transformer 30, a rectifying module, and a filtering module. The switching module 10 is connected to the input winding of the switching transformer 30, the rectifying module is connected to the output winding of the switching transformer 30, and the filtering module is connected to the rectifying module. The switching module 10 can be composed of discrete switching tubes and the electronic components connected thereto, or can be composed of a switching chip and the peripheral electronic components connected thereto, as Figure 9As shown, the switching module 10 is mainly composed of a switching chip IC2. The switching module 10 is powered by the rectified and filtered DC high voltage input, that is, the DC bus voltage. Taking 220V AC as an example, its DC bus voltage generally reaches 300V. Through the high-speed switching action of the switching module 10, a changing current is generated in the primary winding of the switching transformer 30, and a corresponding AC voltage is induced in the secondary winding of the switching transformer 30. After rectification and filtering by the rectification module and the filtering module, low-voltage DC electricity is output. Among them, there can be multiple secondary windings, and the corresponding rectification modules and filtering modules are also multiple, so as to output multiple paths of low-voltage DC electricity, such as Figure 9 As shown, there are three rectification modules and filtering modules, namely the first rectification module 41 and the first filtering module 42, the second rectification module 51 and the second filtering module 52, and the third rectification module 61 and the third filtering module 62. The switching module 10 is also provided with a spike absorption circuit 20. The spike absorption circuit 20 is arranged at the DC bus voltage line end that supplies power to the switching module 10, and plays a role in absorbing interference pulses on the DC bus line. The spike absorption circuit 20 is generally composed of a resistor-capacitor filtering circuit. After the DC bus passes through the spike absorption circuit 20 to filter out interference pulses, it supplies power to the switching module 10. Among them, the positive pole P+ of the DC bus power supply, the spike absorption circuit 20, the primary winding of the switching transformer 30, that is, the above-mentioned input winding, the input pole of the switching tube of the switching module 10, and the output pole of the switching tube of the switching module 10 to the negative pole of the DC bus power supply form a bus current loop CL1, as Figure 2 shown by the dotted line indicating the current loop in the figure. The area of the bus current loop CL1 is 100 square millimeters to 200 square millimeters, and the line width of the bus current loop CL1 is 0.7 millimeters to 2.4 millimeters.

[0027] Since the switching module 10 usually operates in a high-frequency switching state and is powered by a DC high voltage of about 300V, when it switches at high speed, the current in the bus current loop CL1 formed by the traces of the switching transformer 30 and the snubber circuit 20 connected to it is in a high-speed pulsating state corresponding to the operating frequency of the switching module 10. According to the principle of electromagnetic induction, this current loop is likely to emit an electromagnetic field to form an interference source, thereby interfering with the surrounding circuits, especially the control circuit with an MCU. In severe cases, it will interfere with the signals detected by the MCU and / or the control signals output, resulting in abnormal operation. Since the MCU operates at a low voltage such as 3 - 5V, it is extremely vulnerable to interference. In severe cases, the entire control will be abnormal, causing the entire control circuit to malfunction. Therefore, it is very important to reduce the interference electromagnetic field emitted by the bus current loop CL1. Through experimental tests, setting the area of the bus current loop CL1 to 100 square millimeters to 200 square millimeters, such as 140 square millimeters, and the width of the traces of the PCB wiring in this loop to 0.7 millimeters to 2.4 millimeters can significantly reduce the intensity of the emitted electromagnetic field, that is, reduce the noise intensity, thereby effectively reducing the interference to the surrounding circuits, especially the MCU control circuit 91 operating at low voltage, so as to improve the anti-interference ability of the entire control circuit and enhance the working reliability of the entire control circuit.

[0028] In some embodiments of the present invention, as Figure 2 、 Figure 3 and Figure 10 shown, the snubber circuit 20 includes a first capacitor CX1, a second capacitor C1, a first resistor R1, and a first diode D1. The first capacitor CX1 is connected in parallel between the positive and negative poles of the DC bus power input terminal. One end of the first resistor R1 is connected to the positive pole of the DC bus power supply, the other end of the first resistor R1 is connected to the cathode of the first diode D1, and the anode of the first diode D1 is connected to the input pole of the switching transistor of the switching module 10. The second capacitor is connected in parallel with the first resistor R1. The traces connecting one end of the first resistor R1, the first winding of the primary winding of the switching transformer 30, the anode of the first diode D1, and the input pole of the switching transistor of the switching module 10 form a snubber current loop CL2, and the area of the snubber current loop CL2 is 20 square millimeters to 60 square millimeters. The first capacitor CX1 is arranged at the input end of the snubber circuit 20. The switching module 10 is mainly composed of a switching chip IC2, which integrates a switching transistor inside. The switching module 10 can also be composed of discrete electronic components in other embodiments. From Figure 3It can be seen that the snubber circuit 20, together with the first winding of the switching transformer 30 and the trace of the input pole of the switching transistor of the switching module 10, forms a snubber current loop CL2. The snubber current loop CL2 belongs to a small loop within the above-mentioned bus current loop CL1. Since the current in this loop generates an alternating current due to the high-speed operation of the switching transistor, the noise interference generated by the bus current loop CL1 is mainly generated by this loop. Therefore, controlling the intensity of the noise in this loop determines the noise level of the entire bus current loop CL1. Through experimental testing, limiting the area of this loop to 20 square millimeters to 60 square millimeters, such as 40 square millimeters, can effectively limit the generation of its noise, thereby effectively reducing the interference to the surrounding circuit modules.

[0029] In some embodiments of the present invention, such as Figure 2 and Figure 3 shown, the output power supply positive trace and the output power supply negative trace connecting the rectification module, the filtering module, and between the filtering module and the powered electrical load are arranged in parallel, and the distance between the output power supply positive trace and the output power supply negative trace is 0.254 millimeters to 0.35 millimeters. As Figure 9 In, the switching transformer 30 includes two secondary windings, namely the first secondary winding connecting the 9th and 10th pins of the switching transformer 30, and the second secondary winding connecting the 6th and 7th pins of the switching transformer 30. Corresponding to the connection of the first secondary winding are the first rectification module 41 and the first filtering module 42, and the connection of the second secondary winding is the second rectification module 51 and the second filtering module 52. The first rectification module 41 and the first filtering module 42 output a first power supply voltage of +15V, and the second rectification module 51 and the second filtering module 52 output a second power supply voltage of +5V. The two traces L11 and L12 connecting the positive and negative poles of the first power supply voltage of the first rectification module 41 and the first filtering module 42 to the electrical load are arranged in parallel, and the distance between them is relatively small; the two traces L21 and L22 connecting the positive and negative poles of the second power supply voltage of the second rectification module 51 and the second filtering module 52 to the electrical load are also arranged in parallel, and the distance between them is relatively small; this makes the area of the current loop formed by the power supply positive trace and the power supply negative trace as small as possible, thereby reducing the interference to the surrounding circuits, such as the influence of the electromagnetic noise generated by the above-mentioned bus current loop CL1, so that the DC voltage noise output by the power supply is low, more pure and stable, and reduces the interference to the electrical load.

[0030] In some embodiments of the present invention, such as Figures 2 to 9As shown, the PCB board is a double-sided board. The output power supply positive trace and the output power supply negative trace are respectively arranged on two sides of the PCB board. One end of the power supply negative trace is connected to the negative pole of the filtering module, and the other end is connected to the grounding end of the output winding of the switching transformer 30. Since the rectifying diodes in the rectifying module work in a high-speed switching state, for example, the third rectifying diode D3 of the first rectifying module 41 and the fourth rectifying diode D4 of the second rectifying module 51 generate reverse current when they are turned off. Under the influence of the leakage inductance of the switching transformer 30 and the distributed parameters in other circuits, a very fast current change di / dt will be generated, thereby generating a very high-frequency interference with a frequency up to dozens of megahertz. Therefore, if the wiring is unreasonable, strong electromagnetic interference noise will be generated at dynamic nodes such as rectifying diodes and electrolytic capacitors for filtering, which will interfere with the surrounding control circuits. And this electromagnetic interference noise will also be transmitted to other electrical load circuits such as the MCU control circuit 91 along the output power supply trace, thus affecting the working reliability of these load circuits. To avoid this problem, it is necessary to minimize the length of the traces of the electronic components related to these dynamic nodes as much as possible, and minimize the loop area formed by the power supply positive trace and the power supply negative trace connecting these electronic components, so as to reduce the intensity of the noise source. For this reason, there are two measures for improvement. First, place the rectifying diodes such as Figure 2 the third rectifying diode D3 and the fourth rectifying diode D4 as close as possible to the corresponding output winding end of the switching transformer 30. For example, place the third rectifying diode D3 close to the output end of the first secondary winding, and place the fourth rectifying diode D4 close to the second secondary winding, so as to reduce the length of the traces of the electronic components related to the dynamic nodes. Second, arrange the output power supply negative trace (i.e., the ground wire) connected to the negative pole of the electrolytic capacitor of the filtering module and the output power supply positive trace connected to the positive pole of the electrolytic capacitor on two sides of the double-sided PCB board respectively. As Figure 3 , Figure 5 and Figure 8 shown, the power supply negative trace LGND connecting the second electrolytic capacitor E2 and the third electrolytic capacitor E3 is arranged on the back of the PCB board, and it is specifically connected to the second electrolytic capacitor E2 and the third electrolytic capacitor E3 and then to the grounding end of the secondary winding of the switching transformer T1. As Figures 3 to 8 shown, the current loop CL3 formed in this way is as small as possible. Because if they are arranged on the same side of the PCB board, due to wiring limitations, they must bypass some of the electronic components and each other's traces, which increases the loop area formed by the traces. And placing the ground wire on the other side relative to the positive trace, as Figure 5As shown, the trace connecting the electronic components is also on the same side as the positive trace. In this way, the ground trace can directly connect to the negative terminal of the output capacitor and the grounded terminal of the output winding of the transformer, that is, the grounded terminals of the first secondary winding and the second secondary winding, with the shortest distance, so that the loop area between the formed positive line and the ground line is minimized, thereby further effectively reducing the noise source and lowering the electromagnetic noise, thus reducing the interference to other surrounding circuits.

[0031] Furthermore, in some embodiments of the present invention, as Figure 3 , Figure 5 and Figure 8 shown, there are multiple rectification modules and filtering modules. The widths of the power positive trace and the power negative trace connecting the multiple rectification modules and filtering modules are consistent with the over-current magnitudes of the corresponding rectification modules and filtering modules. As Figure 9 shown, the switching power supply circuit outputs multiple direct currents, and the output current varies according to different electrical loads. For example, the first rectification module 41 and the first filtering module 42 output a +15V voltage with a designed current of 150 mA, and the second rectification module 51 and the second filtering module 52 output a +12V voltage with a designed current of 850 mA. Therefore, the output current of the second rectification module 51 and the second filtering module 52 is much larger. From the above embodiments, it can be seen that the rectifying diodes in the rectification modules operating at high speed will generate electromagnetic interference noise and spread it to other electrical loads through the traces, and the traces themselves also form an antenna effect for external radiation. In order to reduce the ability of the traces to transmit interference noise as much as possible, the width of the traces should be minimized as much as possible. Therefore, the width of the traces is consistent with the over-current magnitude, rather than using a single size uniformly. As can be seen from Figure 3 , the trace connecting the second rectification module 51 and the second filtering module 52 is significantly wider than the trace connecting the first rectification module 41 and the first filtering module 42, about half of its width size. This effectively reduces the interference propagation ability of the traces of the first rectification module 41 and the first filtering module 42, thereby further reducing the interference noise generated by the entire power supply circuit and enhancing the working reliability of the entire control circuit. Specifically, the width of the trace connecting the first rectification module 41 and the first filtering module 42 can be from 0.5 mm to 1 mm, such as 0.6 mm, and the width of the trace connecting the second rectification module 51 and the second filtering module 52 can be from 0.8 mm to 1.5 mm, such as 1.3 mm.

[0032] In some embodiments of the present invention, as Figure 3 , Figure 5 and Figure 8As shown, the filtering module includes filtering electrolytic capacitors. The electrolytic capacitors are arranged close to the rectifying diodes of the corresponding rectifying module. The electrolytic capacitors are connected in parallel between the positive output power supply trace and the negative output power supply trace. The rectifying diodes and the electrolytic capacitors are arranged according to the following rule: the direction of the line connecting the two pins of the rectifying diode is not parallel to the direction of the line connecting the two pins of the electrolytic capacitor. As Figure 5 and Figure 2 shown, for the third diode D3 and the second electrolytic capacitor E2 corresponding to the first rectifying module 41 and the first filtering module 42, it can be seen from the pins of the third diode D3 and the silk screen layer of the second electrolytic capacitor E2 that their pins are not arranged in parallel, that is, the line connecting the anode and the cathode of the third diode D3 and the trace connecting the second electrolytic capacitor E2 are not parallel, and there is at least a certain angle. Such an arrangement makes the diffusion direction of the electromagnetic interference source generated at the third diode D3 operating at high speed different from the trace direction, with a certain angle, so that the interference signal transmitted into the trace is reduced. Similarly, the rectifying diodes and filtering capacitors corresponding to other rectifying modules and filtering modules are also arranged in this way. For example, the arrangement direction of the pins of the fourth diode D4 of the second rectifying module 51 and the third electrolytic capacitor E3 of the second filtering module 52, and the arrangement direction of the second diode D2 of the third rectifying module 61 and the first electrolytic capacitor E1 of the third filtering module 62 adopt the same setting, which further reduces the electromagnetic interference noise of the diodes in the rectifying circuit. Preferably, the arrangement direction of the pins of the rectifying diodes and the filtering electrolytic capacitors is perpendicular, that is, the lines connecting the pins of the two components are perpendicular to each other, so as to minimize the electromagnetic interference noise generated by the rectifying diodes.

[0033] The present invention also proposes a power supply circuit device, such as Figures 1 to 9As shown, it includes a PCB board, on which a switching power supply circuit is provided. Some electronic components are installed on the PCB board. Traces formed by copper foils are provided on the PCB board. A switching power supply circuit is formed through the traces and electronic components to convert the input alternating current into an output low-voltage direct current. The switching power supply circuit can output multiple paths of low-voltage direct current, such as +5V, +12V, and +15V, etc., to supply power to different electrical loads. The switching power supply circuit includes a switching module 10, a switching transformer 30, a rectification module, and a filtering module. The switching module 10 is connected to the input winding of the switching transformer 30, the rectification module is connected to the output winding of the switching transformer 30, and the filtering module is connected to the rectification module. The switching module 10 is powered by the input rectified and filtered high-voltage direct current, that is, the DC bus voltage. Taking 220V alternating current as an example, its DC bus voltage can generally reach 300V. Through the high-speed switching action of the switching module 10, a changing current is generated in the primary winding of the switching transformer 30, and a corresponding alternating voltage is induced in the secondary winding of the switching transformer 30. Then, after rectification and filtering by the rectification module and the filtering module, a low-voltage direct current is output. Among them, there can be multiple secondary windings, and the corresponding rectification modules and filtering modules are also multiple to output multiple paths of low-voltage direct current. Such as Figure 3 and Figure 9 As shown, there are three rectification modules and filtering modules, namely the first rectification module 41 and the first filtering module 42, the second rectification module 51 and the second filtering module 52, and the third rectification module 61 and the third filtering module 62.

[0034] The PCB board is a double-sided board. The output power positive trace and the output power negative trace are respectively arranged on two sides of the PCB board. One end of the power negative trace is connected to the negative pole of the filtering module, and the other end is connected to the grounding end of the output winding of the switching transformer 30. Since the rectifier diodes in the rectification module work in a high-speed switching state, as shown in the third rectifier diode D3 of the first rectification module 41 and the fourth rectifier diode D4 of the second rectification module 51, a reverse current is generated when they are turned off. Under the influence of the leakage inductance of the switching transformer 30 and the distributed parameters in other circuits, a very fast current change di / dt will be generated, thereby generating a very high-frequency interference, and its frequency can reach dozens of megahertz. Therefore, if the wiring is unreasonable, strong electromagnetic interference noise will be generated at dynamic nodes such as rectifier diodes and electrolytic capacitors for filtering, which will interfere with the surrounding control circuits. And this electromagnetic interference noise will also be transmitted to other electrical load circuits, such as the MCU control circuit 91, etc., through the output power traces, thus affecting the working reliability of these load circuits. To avoid this problem, it is necessary to minimize the length of the traces of the electronic components related to these dynamic nodes as much as possible, and minimize the loop area formed by the power positive trace and the power negative trace connecting these electronic components, so as to reduce the intensity of the noise source. For this reason, there are two measures to improve. One is to use rectifier diodes such asFigure 3 The third rectifier diode D3 and the fourth rectifier diode D4 in it are arranged as close as possible to the output winding ends corresponding to the switching transformer 30. For example, the third rectifier diode D3 is arranged close to the output end of the first secondary winding, and the fourth rectifier diode D4 is arranged close to the second secondary winding, so as to reduce the length of the traces of the electronic components related to the dynamic nodes. Second, the output power supply negative trace (i.e., the ground wire) connected to the negative electrode of the electrolytic capacitor of the filtering module and the output power supply positive trace connected to the positive electrode of the electrolytic capacitor are respectively arranged on two sides of the double-sided PCB board. As Figures 3 to 8 shown, the current loop CL3 formed in this way is as small as possible. Because if they are arranged on the same side of the PCB board, due to wiring limitations, the two must bypass some of the electronic components and each other's traces, which increases the loop area formed by the traces. And the ground wire is arranged on the other side relative to the positive trace. As Figure 2 and Figure 5 shown, the traces connecting the electronic components are also on the same side as the positive trace. In this way, the ground wire trace can directly connect the negative electrode of the output capacitor and the grounding end of the transformer output winding, that is, the grounding ends of the first secondary winding and the second secondary winding, with the shortest distance, so that the loop area between the positive wire and the ground wire formed is as small as possible, thereby further effectively reducing the noise source and reducing the electromagnetic noise, so as to reduce the interference to other surrounding circuits.

[0035] In some embodiments of the present invention, as Figure 5 , Figure 6 and Figure 9 shown, the filtering module includes a first inductor L1, a first filtering unit 521 connected in parallel to the input end of the first inductor L1, and a second filtering unit 522 connected in parallel to the output end of the first inductor L1. The first filtering unit 521 and the second filtering unit 522 are connected in parallel between the power supply positive trace and the output power supply negative trace. The traces connecting the first inductor L1 are arranged to gradually move away from each other at both ends of the two pins of the first inductor L1. The second filtering module 52 connected to the second rectifying module 51 is a π-type filtering structure, that is, filtering units are connected in parallel on both sides of the first inductor L1, that is, the first filtering unit 521 and the second filtering unit 522. Compared with ordinary capacitive filtering, the π-type filtering circuit has a better filtering effect. As Figure 9 shown, the first trace L31 starting from the first filtering unit 521 is connected to the input side of the first inductor L1, and the second trace L32 starting from the output end of the first inductor L1 is connected to the second filtering unit 522. The first trace L31 and the second trace L32 are arranged to gradually move away from each other and extend from the input end and the output end of the first inductor L1 respectively, that is, the first trace L31 and the second trace L32 are respectively distributed on the outer sides of the two pins of the first inductor L1, rather than there being partial areas of the first trace L31 and the second trace L32 located between the two pins. As Figure 6As shown, the shortest distance between the first trace L31 and the second trace is the spacing H between the two pins of the first inductor L1. If there is a portion of the first trace L31 and the second trace L32 that is less than the spacing H between the two pins of the first inductor L1, it will increase the parasitic capacitance existing between these two traces, thereby affecting the filtering effect of the first inductor L1. Therefore, gradually separating the first trace L31 and the second trace L32 from the input pin and the output pin of the first inductor L1 respectively can correct the filtering ability of the first inductor L1, making the output power supply voltage purer and reducing the noise interference in the power supply voltage.

[0036] In some embodiments of the present invention, as Figure 4 , Figure 5 and Figure 9 shown, the second filtering unit 522 includes a fourth electrolytic capacitor E4 and a fifth electrolytic capacitor E5 connected in parallel, a first trace L31 connecting the first inductor L1 and the fourth electrolytic capacitor E4, and a second trace L32 connecting the first inductor L1 and the fifth electrolytic capacitor E5 are distributed on both sides of the first inductor L1. Further as Figure 6 shown, the trace L32 connecting the output pin of the second inductor further extends to form branches on the left and right sides, corresponding to a first branch trace L41 to the left and a second branch trace L42 to the right, and the lengths of these two branch traces are basically equal and symmetrically distributed relative to the output pin. As Figure 6 shown, the fourth electrolytic capacitor E4 is disposed at one end of the first branch trace L41 on the left side, and the fifth electrolytic capacitor E5 is disposed at the other end of the second branch trace L42 on the right side. This enables the current coming out of the second inductor to be evenly divided into two parts and flow into the fourth electrolytic capacitor E4 and the fifth electrolytic capacitor E5, thereby enabling the fourth electrolytic capacitor E4 and the fifth electrolytic capacitor E5 to have the same filtering effect, thus realizing a two-fold improvement in the filtering ability equivalent to that of one electrolytic capacitor for the fourth electrolytic capacitor E4 and the fifth electrolytic capacitor E5. If a conventional front-back trace method is adopted, that is, the trace coming out of the second inductor is first filtered by the fourth electrolytic capacitor E4 and then further filtered by the fifth electrolytic capacitor E5, the filtering ability of the latter fifth electrolytic capacitor E5 cannot be exerted, so that although they are connected in parallel, they cannot achieve a multiple increase in the filtering ability. Therefore, the above-mentioned trace method of forming branches can effectively improve the filtering ability.

[0037] Preferably, near the first inductor L1, the first branch trace L41 and the second branch trace L42 have a partially overlapping portion, such that the width of the trace after their overlap is the same as the width of each branch trace after branching, which facilitates wiring and reduces the interference caused by over-wide traces when the width after overlap meets the over-current requirement. As Figure 6As shown, the first branch trace L41 and the second branch trace L42 coincide at the second trace L32. Further, the fourth electrolytic capacitor E4 and the fifth electrolytic capacitor E5 are evenly distributed on both sides of the output pin of the second inductor, such that the first branch trace L41 and the second branch trace L42 are completely symmetric with respect to the output pin of the second inductor, and are roughly in a "V" shape distribution. This ensures that the current magnitudes on the first branch trace L41 and the second branch trace L42 are close to or exactly the same, so as to maximize the utilization of the filtering capabilities of the fourth electrolytic capacitor E4 and the fifth electrolytic capacitor E5 and achieve the maximum filtering effect.

[0038] In some embodiments of the present invention, the rectification module and the filtering module are arranged away from the electrical load powered by the output power supply. As Figure 1 , Figure 4 , Figure 7 , Figure 9 and Figure 10 shown, the electrical load of the +15V power supply output by the first rectification module 41 and the first filtering module 42 is mainly a circuit mainly composed of an inverter module for motor drive, i.e., an Intelligent Power Module (IPM). Here, the inverter module includes a first inverter module 93 and a second inverter module 92. The first inverter module 93 is used to drive a high-power motor load such as a compressor, and the second inverter module 92 is used to drive a low-power motor load such as a fan motor. The first rectification module 41 and the first filtering module 42 output a power supply voltage of +12V at the first stage, and its electrical load is a relay and a drive chip for driving the relay to work. Further, the +12V voltage is also stepped down by a step-down module 80 to become a +5V voltage to supply power to the MCU control circuit 91. As can be seen from Figure 4 , these loads are all arranged away from the rectification and filtering modules, and these electrical loads are powered through relatively long power traces from the output end of the filtering module. Because the rectification and filtering modules are in a high-speed state during the working process, especially the rectification diodes of the rectification module, an interfering electromagnetic field, i.e., electromagnetic noise, will be generated during the working process. Therefore, arranging the electrical load away from the rectification module and the filtering module can keep away from the source of electromagnetic noise and reduce interference. Especially for the MCU control circuit 91, it can effectively reduce the interference of the signals received and output by it and improve its working reliability.

[0039] The present invention also proposes a controller, as Figures 1 to 10As shown, the controller includes the power circuit device mentioned in the above embodiments, and an MCU control circuit 91 is further provided. The MCU control circuit 91 includes an MCU for control and a peripheral circuit connected to the MCU. It is characterized in that the PCB is a double-sided board, and a grounding area G_area is provided on the other side of the PCB relative to the area where the traces connecting the MCU and the peripheral circuit are located. The grounding area G_area is electrically connected to the negative pole of the output power supply of the power circuit device. As Figure 1 and Figure 7 shown, the relevant components of the control circuit composed of the MCU and the peripheral circuit connected thereto are installed on the front side of the PCB board. Surface-mounted electronic components can be used. On the back side of the area where the MCU and these electronic components are located, a relatively large area of copper foil is connected to the negative pole of the power supply for supplying power to the MCU control circuit 91, that is, the grounding terminal, to form the grounding area G_area. Since the MCU control circuit 91 transmits low-voltage weak electrical signals such as 5V, and some of the signal frequencies are relatively high, it is easily interfered by the surrounding circuits such as the power circuit in the above embodiments. To further reduce the interference, a relatively large area of grounding is provided in the area where the MCU control circuit 91 board is located, so as to further eliminate the interfering electromagnetic noise through the grounding. Because a large area of grounding is beneficial to reducing the impedance of the ground wire traces, the interference of the electromagnetic noise in the grounding area G_area is reduced. In addition to the MCU control circuit 91, other electrical loads such as comparators arranged close to the MCU can also be grounded, because they also work at low voltages, and the input and output signal frequencies are high, and they are also easily interfered. As Figure 4 and Figure 7 shown, three comparators U1, U2, and U3 arranged close to the MCU are grounded together with the MCU control circuit 91 in a large area.

[0040] In some embodiments of the present invention, the controller further includes a bus power circuit for supplying power to the switching power supply. The bus power circuit outputs a bus positive trace and / or a bus negative trace of the DC bus voltage to form a bus trace. The bus trace and the grounding area G_area are respectively arranged on two sides of the PCB board. The projection of the grounding area G_area in the thickness direction of the PCB board and the bus trace arranged on the other side of the PCB board opposite to the grounding area G_area have a non-overlapping area of the first bus trace. As Figure 1 、 Figure 4 and Figure 7 shown, the bus power supply includes a filter circuit connected to the output of the rectifier bridge BR1, which is mainly composed of large-capacity electrolytic capacitors E8 and E9. For an input AC 220V voltage, the bus positive trace and the bus negative trace connected to the filter circuit provide about 300V of high-voltage direct current. As Figure 4 and Figure 7As shown, the positive bus line includes the positive bus line L61, the positive bus line L62, and the positive bus line L63 connected in sequence. The negative bus line includes the negative bus line L54, the negative bus line L55, and the negative bus line L53 connected in sequence. The negative bus line here and the negative line of the low-voltage direct current output by the above-mentioned switching power supply device are at the same ground potential. However, since the high-voltage direct current is running and output in the positive and negative bus lines here, it supplies power to the electrical load, such as the inverter module for motor drive, that is, the intelligent power module. Since the working current of the IPM module can reach more than 10A, the current in the loop formed by the first bus line, that is, the positive bus line L62 and the negative bus line L55, which supply power to it, is much larger than the current in the loop of the negative line of the low-voltage direct current, with a difference close to or exceeding more than 10 times. Therefore, the interference generated by the negative bus line L55 and the positive bus line L62 is much larger. Therefore, in order to avoid interfering with the surrounding low-voltage current, especially the MCU control circuit 91, the negative bus line L55 and the positive bus line L62 should be set as far as possible from the area where the MCU control circuit 91 is located. From Figure 4 it can be seen that at least a part of the negative bus line L55 and the positive bus line L62 are respectively arranged on two sides of the PCB board, such as Figure 4 and Figure 7 shown, most of the positive bus line L62 is arranged on the back of the PCB board, while the negative bus line L55 is arranged on the front of the PCB board. The paved area G_area where the above-mentioned MCU control circuit 91 is located is arranged on the back of the PCB board. The projection of the first positive bus line in the thickness direction of the PCB board does not coincide with the paved area G_area, that is, they do not overlap in the thickness direction. It can be seen from the figure that there is a certain distance between the negative bus line L55 and the paved area G_area to reduce the interference to the paved area G_area. Although the MCU is set at about the center position of the paved area G_area and is already far from the negative bus line L55, if there is an overlap in the thickness direction between the negative bus line L55 and the paved area G_area, it will interfere with the paved area G_area and enter the MCU through ground conduction, which will interfere with its operation. From Figure 7 it can be seen that there is an overlapping area in the thickness direction between the part of the positive bus line L62 on the back of the PCB board and the part of the negative bus line L55 on the front of the PCB board. Because its overcurrent is large, its wiring width is relatively large. Such an overlapping setting can reduce the area occupied by it on the PCB board, so as to not overlap with the paved area G_area in the thickness direction, thereby further reducing the interference to the MCU control circuit 91.

[0041] Further, in some embodiments of the present invention, the bus trace provided on the other side of the relative copper area G_area of the PCB also has a second bus trace that overlaps with the copper area G_area, and the current-carrying capacity of the first bus trace is greater than that of the second bus trace. From Figure 4 and Figure 7 it can be seen that the second bus trace connected to the first bus is used to supply power to the switching power supply mentioned in the above embodiments. Since the power of the switching power supply is much lower than that of the inverter module, the current-carrying capacity of the second bus is much smaller, and the width of its second bus trace is much narrower. As Figure 4 shown, the second negative bus trace L56 in the second bus trace is located on the front side of the PCB, and its passing area overlaps with the copper area G_area in the thickness direction. It can be seen from the figure that although the potential of the second negative bus trace L56 is the same as that of the copper area G_area, because its current-carrying capacity is relatively higher than that of the MCU control circuit 91, and the two supply power to different electrical loads, the MCU control circuit 91 works with weak electricity, and the switching power supply works with strong electricity. To avoid the interference generated by the switching power supply directly entering through the ground wire, the second negative bus trace L56 uses a separate trace instead of connecting from between the copper areas G_area. Since the current in the second negative bus trace L56 is much lower than the current in the negative bus trace L55, the interference in its trace is also much lower. Therefore, it can partially overlap with the copper area G_area in the thickness direction without interfering with the MCU control circuit 91. Such a trace layout avoids interference while reasonably utilizing the space of the double-sided board to reduce the PCB area occupied by wiring.

[0042] In some embodiments of the present invention, the controller further includes a motor drive module. The motor drive module includes an integrated semiconductor circuit, namely the first inverter module 93 and the second inverter module 92 mentioned in the above embodiments. The first inverter module 93 is mainly composed of the first IPM module IPM1, and the second inverter module 92 is mainly composed of the second IPM module IPM1. It also includes a sampling resistor for sampling the three-phase current output by the inverter module, such as the sampling resistor R15 for sampling the three-phase current output by the sampling IPM1 of the first inverter module 93. The negative bus trace L55 for supplying power to the first IPM module IPM1, the negative bus trace L56 for supplying power to the switching power supply, and the negative bus trace L57 connecting the MCU control circuit 91, i.e., the copper area G_area, are commonly connected to the grounding bonding area near the connection of the sampling resistor R15. As Figure 4As shown, at one end of the sampling resistor R15, corresponding negative traces branch out in all directions to connect to the output power supply that powers each electrical load. The other end of the sampling resistor R15 is connected to the corresponding pin of the first IPM module IPM1 through the bus trace L52. The power positive trace and the power negative trace for each electrical load form respective closed loops. The size of the loop and the overcurrent magnitude in the loop will generate inductive effects to transmit electromagnetic interference signals to the electrical load or other electrical circuits, especially for large current loops. For example, for the DC bus loop that powers the first IPM module IPM1, its current is much larger than that of the power supply loops for the second IPM module IPM2, the MCU control circuit 91, and the switching power supply. Therefore, the area of the DC bus loop should be minimized as much as possible. Since the sampling resistor R15 needs to be close to the relevant pins of the IPM module, specifically the output poles of the switch tubes in the W, V, and U three-phase lower bridge arms within the IPM module. Taking the switch tube as an IGBT (Insulated Gate Bipolar Transistor), it is its emitter; taking the switch tube as a MOS tube (Metal Oxide Semiconductor), it is its source. In this way, the three-phase output current of the IPM collected by it is as accurate as possible to reduce the voltage division and interference caused by the impedance brought by their connection through traces. Therefore, forming a branch at the sampling resistor R15 can greatly reduce the DC bus loop while facilitating PCB wiring, such as Figure 4 and Figure 7 shown, the first DC bus positive trace and the first DC bus negative trace parts are respectively arranged on two sides of the PCB board, and there is an overlapping area in the projection in the thickness direction, which further reduces the area of the DC bus loop, so as to minimize the power trace loop of this maximum interference as much as possible. For other power trace loops, such as the loop for low-voltage DC power supply (+15V) to the first IPM module IPM1 and the second IPM module IPM2, it can be relatively long because the loop current is much smaller, and even the interference caused by the lengthening of the trace is much smaller than that caused by the lengthening of the DC bus loop.

[0043] Furthermore, in the embodiment of the present invention, the width of the negative trace that connects the output power supply of the power supply circuit device to supply power to the semiconductor circuit is smaller than that of the first bus trace, and the negative trace is far away from the first bus trace and the second bus trace, and the negative trace is connected to the ground bonding area. Such as Figure 4As shown, for the weak-current power supply positive trace L65 and the weak-current power supply negative trace L51 at the output of the first filtering module 42 that outputs +15V of the switching power supply, most of their lengths are arranged away from the first bus trace and the second bus trace. Since the weak-current power supply positive trace L65 and the weak-current power supply negative trace L51 transmit low voltages and small currents, while the first bus ground wire and the second bus transmit high voltages and relatively large currents, especially the first bus ground wire has a much larger over-current. Therefore, to avoid interference from the first bus ground wire and the second bus ground wire to the weak-current power supply negative trace, the weak-current power supply negative trace L51 is arranged as far away from them as possible. In Figure 4 , the weak-current power supply positive trace L65 and the weak-current power supply negative trace L51 are routed close to the edge of the PCB board, so as to be as far away from the first bus ground wire and the second bus ground wire as possible. And the weak-current power supply negative trace L51 converges with the first bus ground wire and the second bus ground wire in the above-mentioned grounding combination area. This can minimize the interference caused by the DC bus loop it receives and improve the working reliability of the entire control circuit.

[0044] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0045] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0046] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0047] In the present invention, unless otherwise clearly defined or limited, terms such as "installed", "connected", "linked", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In the present invention, unless otherwise clearly defined or limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0049] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations of the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A power supply circuit device, characterized in that, It includes a PCB board, on which a switching power supply circuit is provided. The switching power supply circuit includes a switching module, a switching transformer, a rectification module and a filtering module. The switching module is connected to the input winding of the switching transformer, the rectification module is connected to the output winding of the switching transformer, and the filtering module is connected to the rectification module. It is characterized in that the switching module is provided with a spike absorption circuit. The switching module is powered by a DC bus power supply. The trace connecting the positive pole of the DC bus power supply, the spike absorption circuit, the input winding of the switching transformer, the input pole of the switching tube of the switching module, the output pole of the switching tube of the switching module to the negative pole of the DC bus power supply forms a bus current loop. The area of the bus current loop is 100 square millimeters to 200 square millimeters, and the width of the trace is 0.7 millimeters to 2.4 millimeters; The spike absorption circuit includes a first capacitor, a second capacitor, a first resistor and a first diode. The first capacitor is connected in parallel between the positive pole and the negative pole of the input end of the DC bus power supply. One end of the first resistor is connected to the positive pole of the DC bus power supply, the other end of the first resistor is connected to the cathode of the first diode, the anode of the first diode is connected to the input pole of the switching tube of the switching module, and the second capacitor is connected in parallel with the first resistor. The trace connecting one end of the first resistor, the first winding of the switching transformer, the anode of the first diode and the input pole of the switching tube of the switching module forms a spike absorption current loop. The area of the spike absorption current loop is 20 square millimeters to 60 square millimeters; The positive output power supply trace and the negative output power supply trace connecting the filtering module to the powered electrical load are arranged in parallel, and the distance between the positive output power supply trace and the negative output power supply trace is 0.254 millimeters to 0.35 millimeters.

2. The power supply circuit device according to claim 1, characterized in that The PCB board is a double-sided board. The positive output power supply trace and the negative output power supply trace are respectively arranged on two sides of the PCB board. One end of the negative power supply trace is connected to the negative pole of the filtering module, and the other end is connected to the grounding end of the output winding of the switching transformer.

3. The power circuit device according to claim 2, characterized in that, There are multiple rectification modules and filtering modules. The widths of the positive power supply traces and the negative power supply traces respectively connecting the multiple rectification modules and the filtering modules are consistent with the over-current magnitudes of the corresponding rectification modules and filtering modules.

4. The power circuit device according to claim 1, characterized in that, The rectification module includes a second diode connected in series to the positive output power supply trace. The second diode is arranged close to the output end of the second winding of the switching transformer output.

5. The power supply circuit device according to claim 4, characterized in that, The filtering module includes a third electrolytic capacitor. The third electrolytic capacitor is arranged close to the second diode. The third electrolytic capacitor is connected in parallel between the positive output power supply trace and the negative output power supply trace. The second diode and the third electrolytic capacitor are arranged according to the following rule: the connection direction of the two pins connecting the second diode is not parallel to the connection direction of the two pins connecting the third electrolytic capacitor.

6. The power supply circuit device according to claim 5, wherein The connection direction of the wire connecting the two pins of the second diode is perpendicular to the connection direction of the wire connecting the two pins of the third electrolytic capacitor.

7. A controller, wherein the controller is provided with the power circuit device according to any one of claims 1 to 6, characterized in that, An MCU control circuit and a motor drive module are also provided. The motor drive module includes an integrated semiconductor circuit and a sampling resistor for sampling the three-phase current output by the semiconductor circuit. Among them, the first bus negative wire for supplying power to the semiconductor circuit, the second bus negative wire for supplying power to the switching power supply, and the third bus negative wire connecting the MCU control circuit are commonly connected to a grounding bonding area near the connection of the sampling resistor.

8. The controller according to claim 7, wherein The width of the negative wire of the output power supply for supplying power to the semiconductor circuit, which connects the power supply circuit device, is smaller than that of the first bus ground wire and the second bus ground wire, and the negative wire is far from the first bus ground wire and the second bus ground wire. The negative wire is connected to the grounding bonding area.

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