Anti-conducted interference boost circuit

Abstract

The utility model relates to an anti-conducted interference boost circuit. Relates to the technical field of inverters. The anti-conducted interference boost circuit comprises inductors P01-P02, a diode D1, a switching tube Q01, a capacitor C01, a switching tube control circuit, a capacitor C02 and a jitter frequency control circuit. Wherein one ends of the inductors P01-P02 are connected with a power supply input end, and the other ends of the inductors P01-P02 are connected with the positive electrode of the diode D1 and the collector electrode of the switching tube Q01; the negative electrode of the diode D1 is connected with the output end of the direct-current bus and one end of the capacitor C02; the other end of the capacitor C02 is grounded; the grid electrode of the switching tube Q01 is connected with one end of the switching tube control circuit and one end of the capacitor C01, and the emitting electrode of the switching tube Q01 is grounded; the other end of the capacitor C01 is grounded; and the jitter frequency control circuit is connected with a BOOST control end in the switching tube control circuit and is used for controlling the driving frequency of the switching tube Q01 to jitter in a frequency range containing a preset working frequency value. The effect of suppressing conducted interference on the basis of not reducing the efficiency of the inverter is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of inverters, in particular to a boost circuit capable of resisting conduction interference. Background Art

[0002] The photovoltaic inverter is composed of a boost circuit and an inverter bridge circuit, wherein the boost circuit is mainly used to boost the DC voltage to the DC voltage required for the inverter output, and the inverter bridge circuit is mainly used to convert the boosted DC voltage into an AC voltage with a fixed frequency. When the boost circuit (Boost Converter) is working, a large amount of high-frequency noise will be generated due to the high-speed switching of the switching elements (such as MOSFET or IGBT), which can be manifested as conducted interference and radiated interference.

[0003] The boost circuit in the related art generally reduces the radiation interference by adding capacitance, but how to effectively suppress the DC conduction interference of the grid-connected inverter without reducing the inverter efficiency has not yet been proposed in the related art. Utility Model Content

[0004] The embodiment of the utility model provides a boost circuit with resistance to conducted interference, which at least solves the problem of how to suppress conducted interference in the boost circuit without reducing the efficiency of the inverter.

[0005] In order to solve the above problems, one aspect of the embodiments of the present utility model provides a boost circuit for resisting conducted interference, comprising:

[0006] Inductors P01-P02, diodes D1, switch tubes Q01, capacitors C01, switch tube control circuits, capacitors C02, and frequency jitter control circuits; among them,

[0007] One end of the inductor P01-P02 is connected to the power input terminal, and the other end is connected to the anode of the diode D1 and the collector of the switch tube Q01;

[0008] The cathode of the diode D1 is connected to the DC bus output terminal and one end of the capacitor C02;

[0009] The other end of capacitor C02 is grounded;

[0010] The gate of the switch tube Q01 is connected to one end of the switch tube control circuit and one end of the capacitor C01, and the emitter of the switch tube Q01 is grounded;

[0011] The other end of capacitor C01 is grounded;

[0012] The frequency jittering control circuit is connected to the BOOST control terminal in the switch tube control circuit, and is used to control the driving frequency of the switch tube Q01 to jitter within a frequency range including a preset operating frequency value.

[0013] In some embodiments, the frequency jitter control circuit includes: a PWM control device, a pin connection circuit and a photocoupler OP; wherein,

[0014] The photocoupler OP is based on a pin connection circuit, one end of which is connected to the PWM control device, and the other end of which is respectively connected to the BOOST control terminal and the ground terminal GND.

[0015] In some of the embodiments, the pin connection circuit includes a first circuit connected to the PWM control device, and a second circuit connected to the BOOST control terminal and the ground terminal GND;

[0016] The first circuit includes a capacitor C1, a capacitor C2, a resistor R1, and a resistor R2; wherein one end of the capacitor C1, the capacitor C2, the resistor R2, and the positive electrode of the light emitting diode in the photocoupler OP are all connected to the first power supply; the other ends of the capacitor C1 and the capacitor C2 are grounded; the other end of the resistor R2 is connected to the resistor R1 and the negative electrode of the light emitting diode; one end of the resistor R1 is connected to the PWM control device, and the other end is connected to the resistor R2 and the negative electrode of the light emitting diode respectively;

[0017] The second circuit includes capacitor C3 and capacitor C4; wherein, one end of the photoelectric coupler OP, capacitor C3 and capacitor C4 are all connected to the second power supply; the other ends of capacitor C3 and capacitor C4 are connected to the ground terminal GND; wherein the voltage value of the first power supply is lower than the voltage value of the second power supply.

[0018] In some embodiments, the control circuit includes a transistor Q02, a resistor R01, a resistor R02, and a resistor R03; wherein,

[0019] The base of transistor Q02 is connected to the BOOST control terminal and one end of resistor R01, the collector of transistor Q02 is grounded, and the emitter of transistor Q02 is connected to one end of resistor R02;

[0020] The other end of the resistor R01 is connected to the gate of the switch tube Q01;

[0021] The other end of the resistor R02 is connected to the gate of the switch tube Q01;

[0022] One end of the resistor R03 is connected to the gate of the switch tube Q01, and the other end is grounded.

[0023] In some of the embodiments, the driving frequency of the switch tube Q01 is jittered with a fixed step value within a frequency range including a preset operating frequency value.

[0024] The boost circuit with resistance to conducted interference provided by the embodiment of the utility model adds a frequency jittering control circuit in the boost circuit to control the driving frequency of the switch tube to jitter within a frequency range that includes a preset operating frequency value, thereby achieving the technical effect of effectively suppressing the excessive conducted interference without reducing the efficiency of the inverter. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the utility model, and for ordinary technicians in this field, other embodiments can be obtained based on these drawings without creative work.

[0026] Figure 1 It is a circuit topology diagram of a boost circuit for resisting conducted interference according to an embodiment of the utility model.

[0027] Figure 2 4 is a circuit topology diagram of a frequency jitter control circuit according to an embodiment of the present utility model.

[0028] Figure 3 Schematic diagram of the jitter trend of the driving frequency of the switch tube in the embodiment of the utility model.

[0029] Figure 4a It is the energy spectrum diagram corresponding to the fixed driving frequency of the switch tube in the related technology.

[0030] Figure 4b This is the energy spectrum diagram corresponding to the jitter driving frequency of the switch tube in the embodiment of the utility model. DETAILED DESCRIPTION

[0031] The embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0032] When the boost converter is working, a large amount of high-frequency noise will be generated due to the high-speed switching of the switching elements. These noises can be manifested as conducted interference and radiated interference. Among them, the high-frequency radiated interference is because the transient current changes generated by the fast switching action produce rapid voltage changes in the circuit, which in turn causes changes in the electromagnetic field, and causes electromagnetic compatibility problems through space propagation. The boost circuit in the related technology generally reduces the radiated interference by increasing the capacitance. DC conducted interference mainly refers to the electromagnetic interference signal transmitted through the wire, which includes both differential mode interference (unbalanced voltage between the live wire and the neutral wire) and common mode interference (voltage between the live wire, the neutral wire and the earth). The boost circuit in the related technology has not yet proposed a good solution for the suppression of conducted interference. With the continuous development of inverter technology and the increase in the installed capacity of inverters, the photovoltaic inverter standards are also constantly updated. When the input distance of the photovoltaic grid-connected inverter is more than 30m from the component installation, it is necessary to enforce the DC conducted disturbance interference test, which makes many inverter manufacturers unable to pass this test.

[0033] In order to solve the above problems, the embodiment of the utility model provides a boost circuit with anti-conduction interference, such as Figure 1 As shown, the boost circuit for resisting conducted interference includes: inductors P01-P02, diodes D1, switches Q01, capacitors C01, switches control circuits, capacitors C02 and frequency jittering control circuits; wherein, one end of the inductors P01-P02 is connected to the power input end, and the other end is connected to the positive electrode of the diode D1 and the collector of the switches Q01; the negative electrode of the diode D1 is connected to the DC bus output end and one end of the capacitor C02; the other end of the capacitor C02 is grounded; the gate of the switches Q01 is connected to one end of the switches control circuit and one end of the capacitor C01, and the emitter of the switches Q01 is grounded; the other end of the capacitor C01 is grounded; the frequency jittering control circuit is connected to the BOOST control end in the switches control circuit, and is used to control the driving frequency of the switches Q01 to jitter within a frequency range including a preset operating frequency value.

[0034] Among them, the above-mentioned frequency jittering control circuit is used to control the driving frequency of the switch tube Q01 to jitter within a frequency range including a preset operating frequency value to disperse the concentrated interference spectrum, thereby realizing "spectrum shifting", thereby achieving the technical effect of reducing conducted interference.

[0035] In some of the embodiments, the frequency jittering control circuit includes: a PWM control device, a pin connection circuit and a photocoupler OP; wherein the photocoupler OP is based on the pin connection circuit, one end of which is connected to the PWM control device, and the other end is respectively connected to the BOOST control terminal and the ground terminal GND.

[0036] Specifically, Figure 2The topological circuit diagram corresponding to the frequency jitter control circuit is shown. After the PWM control device inputs the electrical signal, the light emitter (light emitting diode) in the photocoupler OP emits light, and the light receiver receives the light to generate photocurrent, and then transmits the electrical signal to the switch tube Q01 through the BOOST control terminal, thereby realizing the control of the driving frequency of the switch tube Q01, and controlling the driving frequency to jitter within the frequency range including the preset operating frequency value.

[0037] In some of the embodiments, the pin connection circuit includes a first circuit connected to the PWM control device and a second circuit connected to the BOOST control terminal and the ground terminal GND; the first circuit includes capacitor C1, capacitor C2, resistor R1, and resistor R2; wherein, one end of capacitor C1, capacitor C2, resistor R2 and the positive electrode of the light-emitting diode in the photoelectric coupler OP are all connected to the first power supply; the other ends of capacitor C1 and capacitor C2 are grounded; the other end of resistor R2 is connected to resistor R1 and the negative electrode of the light-emitting diode; one end of resistor R1 is connected to the PWM control device, and the other end is respectively connected to resistor R2 and the negative electrode of the light-emitting diode; the second circuit includes capacitor C3 and capacitor C4; wherein, one end of the photoelectric coupler OP, capacitor C3, and capacitor C4 are all connected to the second power supply; the other ends of capacitor C3 and capacitor C4 are connected to the ground terminal GND; wherein, the voltage value of the first power supply is lower than the voltage value of the second power supply.

[0038] According to the embodiment of the utility model, the operating frequency value of the switch tube Q01 can be set to 39kHz, and the frequency jitter control circuit controls the driving frequency of the switch tube Q01 to periodically change up and down by 1kHz with 39khz as the center; that is, starting from 38khz, it increases by 0.04% step to 40khz, and repeats the cycle (the driving frequency jitter trend diagram is shown in FIG. Figure 3 It should be noted that the above values ​​are only examples and are not intended to limit the present application. The preset operating frequency, the frequency range of the jitter, and the growth step value during the frequency jitter process can all be adjusted according to the actual operating conditions.

[0039] In some of the embodiments, the frequency jittering control circuit may further control the driving frequency of the switch tube Q01 to randomly jitter within a frequency range including a preset operating frequency value, rather than jittering according to a fixed step value.

[0040] According to a specific implementation of the embodiment of the utility model, when the frequency of the switch tube Q01 controlled by the frequency jitter control circuit starts at 38 khz, and increases by 0.04% step to 40 khz, during the reciprocating cycle, the energy frequency corresponding to the DC conduction is as follows: Figure 4b Compared with the fixed driving frequency of the light-emitting tube in the related art (the power spectrum corresponding to DC conduction is shown in Figure 4a ). Figure 4a and Figure 4b It can be seen that the frequency jitter control circuit provided by the present application realizes a dispersed and concentrated interference spectrum by controlling the driving frequency of the switch tube Q01 to jitter within a frequency range including a preset operating frequency value, which can significantly improve the DC conduction interference, that is, it has achieved a good effect in suppressing the conduction interference of the boost circuit. In addition, the solution provided by the utility model has fewer changes to the original boost circuit, avoiding the impact on the inverter efficiency, and can also effectively reduce the line layout cost.

[0041] Among them, the control terminal BOOST connected to the switch tube control circuit is used to input a control high level signal or a control low level signal, and the switch tube control circuit is used to control the switch tube Q01 to be turned on or off. Specifically, the control terminal BOOST inputs a control high level signal through the switch tube control circuit to control the switch tube Q01 to be turned on. When the switch tube Q01 is turned on, the power supply charges the inductor P01-P02. Since the input is direct current, the current on the inductor P01-P02 increases linearly at a certain ratio. As the current of the inductor P01-P02 increases, some energy is stored in the inductor. Among them, the diode D1 is used to prevent the capacitors C02 and C03 from discharging to the ground. When the energy stored in the inductor P01-P02 is saturated, the control terminal BOOST inputs a control low level signal through the control circuit to control the switch tube Q01 to be turned off. When the switch tube Q01 is turned off, due to the current holding characteristics of the inductor, the current flowing through the inductor P01-P02 will not immediately become 0, but slowly change from the value when the charging is completed to 0. The inductor starts to charge the capacitor C03, and the voltage across the capacitor C03 increases. At this time, the voltage is higher than the input voltage, and the boost is completed.

[0042] In the above embodiment, capacitor C01 is the input capacitor of switch tube Q01, which is used to eliminate the high-frequency oscillation of the driving voltage VGE of switch tube Q01; C02 is the high-frequency absorption capacitor between the output ends of the boost circuit. By increasing capacitor C01 to reduce radiation interference, the high-frequency oscillation of switch tube Q01 is reduced to suppress the radiation of the grid-connected inverter, so that the high-frequency interference at the collector and emitter ends of switch tube Q01 is absorbed and cannot be radiated. Adding capacitor C02 eliminates the interference at the output end, achieving the purpose of suppressing the excessive radiation interference.

[0043] In some embodiments, the control circuit includes a transistor Q02, a resistor R01, a resistor R02, and a resistor R03; wherein the base of the transistor Q02 is connected to the BOOST control terminal and one end of the resistor R01, the collector of the transistor Q02 is grounded, and the emitter of the transistor Q02 is connected to one end of the resistor R02; the other end of the resistor R01 is connected to the gate of the switch tube Q01; the other end of the resistor R02 is connected to the gate of the switch tube Q01; one end of the resistor R03 is connected to the gate of the switch tube Q01, and the other end is grounded.

[0044] Among them, the above-mentioned resistor R01 is the on-resistance, which is the on-resistance when the voltage of the switch tube Q01 driving voltage Vge is turned on; the resistor R02 is the off-resistance; and the resistor R03 is the resistance of the switch tube Q01 in a fixed state of the driving voltage Vge. The magnitude of the driving voltage Vge is controlled by controlling the conduction or disconnection of the transistor Q02 through the control terminal BOOST, thereby realizing the control of the conduction or disconnection of the switch tube Q01.

[0045] The above-mentioned boost circuit with resistance to conducted interference provided by the embodiment of the utility model comprises: an inductor P01-P02, a diode D1, a switch tube Q01, a capacitor C01, a switch tube control circuit, a capacitor C02 and a frequency jittering control circuit; wherein, one end of the inductor P01-P02 is connected to the power input end, and the other end is connected to the positive electrode of the diode D1 and the collector of the switch tube Q01; the negative electrode of the diode D1 is connected to the power output end and one end of the capacitor C02; the other end of the capacitor C02 is grounded; the gate of the switch tube Q01 is connected to one end of the switch tube control circuit and one end of the capacitor C01; the other end of the capacitor C01 is grounded; the frequency jittering control circuit is connected to the BOOST control end in the switch tube control circuit, and is used to control the driving frequency of the switch tube Q01 to jitter within a frequency range including a preset operating frequency value. By adding a frequency jittering control circuit in the boost circuit to control the driving frequency of the switch tube to jitter within a frequency range that includes a preset operating frequency value, the technical effect of effectively suppressing the excessive conduction interference is achieved without reducing the efficiency of the inverter.

[0046] It should be noted that the term "including" and its variations used in the embodiments of the present invention are open inclusions, that is, "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "multiple" mentioned in the embodiments of the present invention are illustrative and not restrictive. Those skilled in the art should understand that unless the context clearly indicates otherwise, it should be understood as "one or more".

[0047] The term "embodiment" in this specification refers to specific features, structures or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of the present utility model. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. The various embodiments in this specification are described in a related manner, and the same or similar parts between the various embodiments refer to each other. In particular, for the device, equipment, and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts refer to the partial description of the method embodiment.

[0048] Those skilled in the art to which the present invention belongs may make various modifications or additions to the specific embodiments described, or replace them in a similar manner, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0049] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of protection. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the scope of protection of the utility model. Therefore, the scope of protection of the utility model shall be based on the attached claims.

Claims

1. A boost circuit for resisting conduction interference, characterized in that: include: Inductors P01-P02, diodes D1, switch tubes Q01, capacitors C01, switch tube control circuits, capacitors C02, and frequency jitter control circuits; among them, One end of the inductor P01-P02 is connected to the power input terminal, and the other end is connected to the anode of the diode D1 and the collector of the switch tube Q01; The cathode of the diode D1 is connected to the DC bus output terminal and one end of the capacitor C02; The other end of the capacitor C02 is grounded; The gate of the switch tube Q01 is connected to one end of the switch tube control circuit and one end of the capacitor C01, and the emitter of the switch tube Q01 is grounded; The other end of the capacitor C01 is grounded; The frequency jittering control circuit is connected to the BOOST control terminal in the switch tube control circuit, and is used to control the driving frequency of the switch tube Q01 to jitter within a frequency range including a preset operating frequency value.

2. The circuit according to claim 1, characterized in that The frequency jitter control circuit includes: a PWM control device, a pin connection circuit and a photoelectric coupler OP; wherein, Based on the pin connection circuit, one end of the photocoupler OP is connected to the PWM control device, and the other end is respectively connected to the BOOST control terminal and the ground terminal GND.

3. The circuit according to claim 2, characterized in that The pin connection circuit includes a first circuit connected to the PWM control device, and a second circuit connected to the BOOST control terminal and the ground terminal GND; The first circuit includes a capacitor C1, a capacitor C2, a resistor R1, and a resistor R2; wherein one end of the capacitor C1, the capacitor C2, the resistor R2, and the positive electrode of the light-emitting diode in the photoelectric coupler OP are all connected to a first power supply; the other ends of the capacitor C1 and the capacitor C2 are grounded; the other end of the resistor R2 is connected to the resistor R1 and the negative electrode of the light-emitting diode; one end of the resistor R1 is connected to the PWM control device, and the other end is connected to the resistor R2 and the negative electrode of the light-emitting diode respectively; The second circuit includes capacitor C3 and capacitor C4; wherein, one end of the photoelectric coupler OP, the capacitor C3, and the capacitor C4 are all connected to the second power supply; the other ends of the capacitor C3 and the capacitor C4 are connected to the ground terminal GND; wherein the voltage value of the first power supply is lower than the voltage value of the second power supply.

4. The circuit according to claim 1, characterized in that The control circuit includes transistor Q02, resistor R01, resistor R02, and resistor R03; wherein, The base of the transistor Q02 is connected to the BOOST control terminal and one end of the resistor R01, the collector of the transistor Q02 is grounded, and the emitter of the transistor Q02 is connected to one end of the resistor R02; The other end of the resistor R01 is connected to the gate of the switch tube Q01; The other end of the resistor R02 is connected to the gate of the switch tube Q01; One end of the resistor R03 is connected to the gate of the switch tube Q01 , and the other end is grounded.

5. The circuit according to claim 1, characterized in that The driving frequency of the switch tube Q01 is jittered with a fixed step value within a frequency range including a preset operating frequency value.

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