Conversion circuit compatible with AC / DC micro electric energy input and control method

Abstract

The invention discloses a conversion circuit control system and method compatible with AC / DC micro electric energy input. The circuit comprises a first composite device M1 and a second composite device M2, wherein the first composite device M1 comprises a first low-threshold transistor which is reversely connected in parallel with a diode; the second composite device M2 comprises a second low-threshold transistor which is in anti-parallel connection with a diode; the third composite device M3 comprises a third low-threshold transistor which is in anti-parallel connection with a diode; the fourth composite device M4 comprises a fourth low-threshold transistor which is in anti-parallel connection with a diode; the fifth composite device M5 comprises a fifth low-threshold transistor which is in anti-parallel connection with a diode; the sixth composite device M6 comprises a sixth low-threshold transistor which is in anti-parallel connection with a diode; the transistor is switched on or switched off according to the PWM signal, and when a direct-current power supply is input, the input voltage is boosted; when an AC power supply is input, an input voltage is boosted and rectified. The same PMIC chip can be applied to different environment energy collection scenes such as alternating current or direct current, the application range of the chip is widened, and large-area popularization and application of the chip are facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of online monitoring node energy supply for power transmission and transformation equipment, and more specifically, the present invention relates to a conversion circuit and a control method that are compatible with AC and DC micro-electric energy inputs and have a cold start function. Background Art

[0002] The construction of the UHV DC transmission backbone grid and networking is an important foundation for realizing the energy development transformation strategy and promoting the clean and green way to meet the global electricity demand. With the successive commissioning of many HVDC transmission lines, higher requirements are put forward for the safe and reliable operation of the core equipment of the HVDC converter station. The converter valve is the core equipment in the UHV DC converter station. It is expensive and plays an important role. Once the converter valve equipment fails, it will not only cause the shutdown of DC transmission, but in severe cases, it may cause the converter valve or valve hall to catch fire, thus causing a major safety accident. To address this challenge, embedded micro-intelligent sensors can be used to monitor the temperature and other physical quantities of the converter valve equipment online. However, since the converter valve is a high-voltage and high-current environment, it is very challenging to obtain energy at high potential to power the sensor node. If lithium batteries are used for power supply, the safety of lithium batteries is poor and there is a risk of explosion. At the same time, the regular replacement of a large number of batteries greatly increases the operation and maintenance costs of the converter valve equipment. How to safely and reliably solve the problem of sensor power supply is the key to realizing long-term online monitoring of physical quantities such as the temperature of the converter valve equipment.

[0003] The prior art document (CN113630003A) discloses an energy harvesting and control system based on pseudo-load regulation and voltage stabilization. The solution in this technical document only supports DC source input and is not compatible with AC source input. In addition, its design adopts discrete circuit design and does not implement chip circuit design, making it difficult to meet miniaturized application scenarios. Summary of the invention

[0004] A first aspect of the present invention provides a conversion circuit compatible with AC and DC micro-electric energy input, specifically comprising:

[0005] The first composite device M1 includes a first low threshold transistor anti-parallel connected with a diode; the second composite device M2 includes a second low threshold transistor anti-parallel connected with a diode; the third composite device M3 includes a third low threshold transistor anti-parallel connected with a diode; the fourth composite device M4 includes a fourth low threshold transistor anti-parallel connected with a diode; the fifth composite device M5 includes a fifth low threshold transistor anti-parallel connected with a diode; the sixth composite device M6 includes a sixth low threshold transistor anti-parallel connected with a diode;

[0006] The diode in the first composite device M1 is connected to the energy storage capacitor;

[0007] An input terminal of the first composite device M1 is connected to an input terminal of the second composite device M2;

[0008] Output ends of the third composite device M3, the fourth composite device M4, the fifth composite device M5 and the sixth composite device M6 are connected;

[0009] The input end of the third composite device M3 and the input end of the fifth composite device M5 are connected to the output end of the first composite device M1 ; the input end of the fourth composite device M4 and the input end of the sixth composite device M6 are connected to the output end of the second composite device M2 .

[0010] A second aspect of the present invention provides a control method for a conversion circuit compatible with AC and DC micro-power inputs, based on the above-mentioned conversion circuit compatible with AC and DC micro-power inputs, comprising:

[0011] Step 1, collecting energy from the environment and converting it into electrical energy and transmitting it to the conversion circuit;

[0012] Step 2: The voltage at the maximum power point is transmitted to the error amplifier through MPPT, compared with the reference voltage, and the error is calculated and transmitted to the PWM module to generate a PWM signal to control the operation of the conversion circuit;

[0013] Step 3, when the input voltage of the conversion circuit does not reach the working voltage, the conversion circuit is cold started; when the DC power supply is input, the input voltage is boosted; when the AC power supply is input, if the input voltage is lower than the working voltage, the input voltage is boosted and rectified; if the input voltage is higher than the working voltage, the input voltage is rectified;

[0014] Step 4: The linear regulator compares the voltage output by the converter in step 3 with the reference voltage, adjusts internal components, and provides a stable DC voltage VDC output.

[0015] Preferably, the operation process of the conversion circuit when the DC power supply is input is specifically as follows:

[0016] After the control circuit is started, the second low threshold transistor, the third low threshold transistor, the fourth low threshold transistor and the sixth low threshold transistor in the circuit are placed in an off state through a PWM control signal.

[0017] Preferably, in the circuit, only the fifth low-threshold transistor is in a controllable switch state, wherein the anti-parallel diode of the first low-threshold transistor is always in an operating mode, and at this time the circuit is a typical DC boost circuit.

[0018] Preferably, the operation process of the conversion circuit when AC power is input is specifically as follows:

[0019] After the control circuit is started, the fifth low threshold transistor and the sixth low threshold transistor in the circuit are placed in a controllable switch state through a PWM control signal, and the first low threshold transistor, the second low threshold transistor, the third low threshold transistor and the fourth low threshold transistor do not work.

[0020] Preferably, the anti-parallel diodes of the first low threshold transistor, the second low threshold transistor, the third low threshold transistor and the fourth low threshold transistor are in operation mode to form a rectifier circuit.

[0021] Preferably, when the input voltage of the conversion circuit is lower than the operating voltage, the fifth low threshold transistor and the sixth low threshold transistor are turned on to form a loop with the inductor L and the AC source to charge the inductor.

[0022] Preferably, the circuit operation process when the AC input voltage of the conversion circuit is less than the operating voltage is specifically as follows:

[0023] When the inductor energy reaches a certain value, the fifth low threshold transistor and the sixth low threshold transistor are turned off, and the input voltage is boosted by a rectification circuit formed by anti-parallel diodes of the first low threshold transistor, the second low threshold transistor, the third low threshold transistor and the fourth low threshold transistor. The fifth low threshold transistor and the sixth low threshold transistor are used to accumulate energy for charging the inductor.

[0024] Preferably, the circuit operation process when the AC input voltage of the conversion circuit is higher than the operating voltage is specifically as follows:

[0025] When the input voltage of the conversion circuit is higher than the operating voltage, the fifth low-threshold transistor and the sixth low-threshold transistor stop working, and the rectifier circuit composed of the anti-parallel diodes of the first low-threshold transistor, the second low-threshold transistor, the third low-threshold transistor and the fourth low-threshold transistor takes over the work to rectify the input voltage.

[0026] Preferably, the PWM module adjusts the output PWM control signal according to the error signal of the error amplifier, thereby controlling the conversion circuit to adjust the output voltage.

[0027] The beneficial effect of the present invention is that, compared with the prior art, the present invention proposes a power management interface circuit that is compatible with both AC and DC micro-electric energy inputs. The circuit can be used as a part of the entire power management integrated circuit (PMIC), thereby enabling the same PMIC chip to be used in different environmental energy collection scenarios such as AC or DC, thereby increasing the application scope of the chip and facilitating the large-scale promotion and application of the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a topological diagram of a conversion circuit compatible with AC and DC input sources;

[0029] Figure 2 It is a topological diagram of a conversion circuit with a DC input source having a cold start function;

[0030] Figure 3 It is a topological diagram of a conversion circuit with a cold start function for an AC input source;

[0031] Figure 4 It is an overall implementation scheme for a conversion circuit control system that is compatible with AC and DC input sources. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only part of the embodiments of the present invention, not all of them. Based on the spirit of the present invention, other embodiments obtained by ordinary technicians in this field without creative work are all within the scope of protection of the present invention.

[0033] The first embodiment of the present invention provides a conversion circuit compatible with AC and DC micro-power input, wherein the micro-power input generally refers to a voltage input of less than 0.5V, and most preferably a voltage input of about 300mV. The conversion circuit topology compatible with AC and DC input power supply is as follows: Figure 1 As shown, the circuit topology mainly includes:

[0034] The first composite device M1 includes a first low threshold transistor (NMOS type) anti-parallel connected to a diode; the second composite device M2 includes a second low threshold transistor anti-parallel connected to a diode; the third composite device M3 includes a third low threshold transistor anti-parallel connected to a diode; the fourth composite device M4 includes a fourth low threshold transistor anti-parallel connected to a diode; the fifth composite device M5 includes a fifth low threshold transistor anti-parallel connected to a diode; the sixth composite device M6 includes a sixth low threshold transistor anti-parallel connected to a diode;

[0035] The diode in the first composite device M1 is connected to the energy storage capacitor;

[0036] An input terminal of the first composite device M1 is connected to an input terminal of the second composite device M2;

[0037] The input end of the third composite device M3 and the input end of the fifth composite device M5 are connected to the output end of the first composite device M1; the input end of the fourth composite device M4 and the input end of the sixth composite device M6 are connected to the output end of the second composite device M2;

[0038] Output ends of the third composite device M3 , the fourth composite device M4 , the fifth composite device M5 and the sixth composite device M6 are connected.

[0039] The device can be implemented in an integrated circuit, wherein a typical startup voltage of the transistor is 0.3V, that is, the device can be started when an input voltage is 300mV, without requiring a boost device such as an external transformer.

[0040] A second embodiment of the present invention provides a method for controlling a conversion circuit compatible with AC and DC micro-electric energy input, which is used to control the conversion circuit described in Embodiment 1, comprising:

[0041] Step 1: Collect tiny energy in the environment, including light energy, heat energy, energy generated by mechanical vibration, etc., and convert it into electrical energy and transmit it to the conversion circuit. The electrical power output is about 100uW, the voltage output is generally about 300mV, and the maximum does not exceed 0.5V;

[0042] In a preferred but non-limiting embodiment of the present invention, step 1 specifically comprises:

[0043] The heat generated by the converter valve body during operation and the temperature difference between its surface and the surrounding air can be used to generate electricity. The environmental energy conversion output is generally a DC power supply. The vibration of converter valve components such as reactors can also be used to generate electricity. The environmental energy conversion output is generally an AC source.

[0044] Step 2: The voltage at the maximum power point is transmitted to the error amplifier through MPPT, compared with the reference voltage, and the error is calculated and transmitted to the PWM module to generate a PWM signal to control the operation of the conversion circuit;

[0045] Step 3, when the input voltage of the conversion circuit does not reach the working voltage, the conversion circuit is cold started; when the DC power supply is input, the input voltage is boosted; when the AC power supply is input, if the input voltage is lower than the working voltage, the input voltage is boosted and rectified; if the input voltage is higher than the working voltage, the input voltage is rectified;

[0046] In a preferred but non-limiting embodiment of the present invention, step 3 specifically comprises:

[0047] The working principle of the conversion circuit when facing DC power input is as follows Figure 2As shown. During the cold start process, when the power supply voltage does not reach the normal starting working voltage, the current charges the subsequent energy storage capacitor through the diode connected in parallel to the first low threshold transistor in the first composite device M1. When the charging voltage reaches a certain working voltage, the control circuit is started, and the second low threshold transistor in the second composite device M2, the third low threshold transistor in the third composite device M3, the fourth low threshold transistor in the fourth composite device M4, and the sixth low threshold transistor in the sixth composite device M6 in the circuit are always placed in the off state through the control signal. Only the fifth low threshold transistor in the fifth composite device is in the switching state in the circuit, wherein the diode connected in parallel to the first low threshold transistor in the first composite device is always in the working mode. At this time, the circuit is a typical DC boost circuit, which can realize energy collection of an input voltage of 0.3V.

[0048] The working principle of the conversion circuit for AC power input is as follows Figure 3 As shown. During the cold start process, when the power supply voltage does not reach the normal starting working voltage, the current charges the subsequent energy storage capacitor through the diode connected in parallel with the first low threshold transistor. When the charging voltage reaches a certain working voltage, the control circuit starts, and the fifth low threshold transistor and the sixth low threshold transistor in the circuit are placed in a controllable switch state through a control signal, and the first low threshold transistor, the second low threshold transistor, the third low threshold transistor and the fourth low threshold transistor do not work, and the diode is in working mode to form a rectifier circuit. When the input voltage is low, the fifth low threshold transistor and the sixth low threshold transistor are turned on to form a loop with the inductor L and the AC source to charge the inductor. When the energy stored in the inductor reaches the maximum value (that is, the inductor current reaches the maximum value, and the current value is related to the power supply voltage and the internal impedance of the power supply at this time), the fifth low threshold transistor and the sixth low threshold transistor are turned off, and the energy stored in the inductor is transferred to the subsequent circuit through the rectifier circuit formed by the diode connected in parallel with the first low threshold transistor, the second low threshold transistor, the third low threshold transistor and the fourth low threshold transistor. On the basis of the first low threshold transistor, the second low threshold transistor, the third low threshold transistor and the fourth low threshold transistor anti-parallel diode forming a rectifier circuit, the design of using the fifth low threshold transistor and the sixth low threshold transistor to accumulate energy for charging the inductor realizes the boosting of the small voltage input. When the input voltage is high, the low threshold transistors in the fifth low threshold transistor and the sixth low threshold transistor stop working, and the rectifier circuit formed by the first low threshold transistor, the second low threshold transistor, the third low threshold transistor and the fourth low threshold transistor anti-parallel diode takes over the work.

[0049] Step 4: The linear regulator compares the voltage output by the conversion circuit in step 3 with the reference voltage, adjusts internal components, and provides a stable DC voltage VDC output.

[0050] As a prominent substantive feature of the present invention and one of the significant advances it brings to the prior art, the same conversion circuit topology can be compatible with both AC and DC input sources through a control system, and the chip cold start can be achieved through circuit control; and the same power management chip can be compatible with AC and DC input power supplies, which increases the versatility and application scenarios of the chip.

[0051] The third embodiment of the present invention provides a conversion circuit control system compatible with AC and DC micro-electric energy input, and runs the conversion circuit control method described in embodiment 2, such as Figure 4 As shown, the converter module corresponds to the conversion circuit described in Example 1, and the conversion circuit control system includes the following main functional modules:

[0052] Environmental energy collection device: used to collect tiny energy from the environment and convert it into electrical energy and transmit it to the converter;

[0053] Drive circuit: provides power for linear regulator, PWM module, maximum power tracking MPPT, error amplifier and other functional modules;

[0054] MPPT module: It realizes maximum power tracking based on the open circuit voltage method, and then determines the maximum power point, and sends the voltage of the maximum power point to the error amplifier;

[0055] PWM module: adjusts the duty cycle of the output PWM signal according to the error signal output by the error amplifier, and provides the PWM signal as a control signal to the low threshold transistor inside the converter to control the operation of the converter;

[0056] Converter module: has cold start function and is compatible with AC and DC input sources;

[0057] Linear regulator: Compares the converter output voltage with the reference voltage. Based on the comparison result, the linear regulator adjusts the working state of its internal components to provide a stable DC voltage VDC output.

[0058] The present disclosure may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A conversion circuit compatible with AC and DC micro-electric energy input, It is characterized in that include: The first composite device M1 includes a first low threshold transistor anti-parallel connected with a diode; the second composite device M2 includes a second low threshold transistor anti-parallel connected with a diode; the third composite device M3 includes a third low threshold transistor anti-parallel connected with a diode; the fourth composite device M4 includes a fourth low threshold transistor anti-parallel connected with a diode; the fifth composite device M5 includes a fifth low threshold transistor anti-parallel connected with a diode; the sixth composite device M6 includes a sixth low threshold transistor anti-parallel connected with a diode; The diode in the first composite device M1 is connected to the energy storage capacitor; An input terminal of the first composite device M1 is connected to an input terminal of the second composite device M2; The input end of the third composite device M3 and the input end of the fifth composite device M5 are connected to the output end of the first composite device M1; the input end of the fourth composite device M4 and the input end of the sixth composite device M6 are connected to the output end of the second composite device M2; Output ends of the third composite device M3 , the fourth composite device M4 , the fifth composite device M5 and the sixth composite device M6 are connected.

2. A control method for a conversion circuit compatible with AC and DC micro-power input, based on the conversion circuit compatible with AC and DC micro-power input as claimed in claim 1, It is characterized in that include: Collect energy from the environment and convert it into electrical energy and transmit it to the conversion circuit; The voltage at the maximum power point is transmitted to the error amplifier through MPPT, compared with the reference voltage, and the error is calculated and transmitted to the PWM module to generate a PWM signal to control the conversion circuit; When the input voltage of the conversion circuit does not reach the working voltage, the conversion circuit is cold started; when the DC power supply is input, the input voltage is boosted; when the AC power supply is input, if the input voltage is lower than the working voltage, the input voltage is boosted and rectified; if the input voltage is higher than the working voltage, the input voltage is rectified; The linear regulator compares the voltage output by the conversion circuit with the reference voltage, adjusts the internal components, and provides a stable DC voltage VDC output.

3. A control method for a conversion circuit compatible with AC and DC micro-electric energy input as claimed in claim 2, Features: The operation process of the conversion circuit when DC power is input is as follows: After the conversion circuit is started, the second low threshold transistor, the third low threshold transistor, the fourth low threshold transistor and the sixth low threshold transistor in the circuit are placed in an off state through a PWM control signal.

4. A control method for a conversion circuit compatible with AC and DC micro-electric energy input as claimed in claim 3, Features: In the circuit, only the fifth low-threshold transistor is in a controllable switch state, wherein the anti-parallel diode of the first low-threshold transistor is always in a working mode, and at this time the circuit is a typical DC boost circuit.

5. A control method for a conversion circuit compatible with AC and DC micro-electric energy input as claimed in claim 2, Features: The operation process of the conversion circuit when AC power is input is as follows: After the conversion circuit is started, the fifth low threshold transistor and the sixth low threshold transistor in the circuit are placed in a controllable switch state through a PWM control signal, and the first low threshold transistor, the second low threshold transistor, the third low threshold transistor and the fourth low threshold transistor do not work.

6. A control method for a conversion circuit compatible with AC and DC micro-electric energy input as claimed in claim 5, Features: The anti-parallel diodes of the first low threshold transistor, the second low threshold transistor, the third low threshold transistor and the fourth low threshold transistor are in the working mode to form a rectification circuit.

7. A control method for a conversion circuit compatible with AC and DC micro-electric energy input as claimed in claim 5, Features: The circuit working process when the AC input voltage of the conversion circuit is less than the working voltage is as follows: When the input voltage of the conversion circuit is lower than the operating voltage, the fifth low threshold transistor and the sixth low threshold transistor are turned on to form a loop with the inductor L and the AC power supply to charge the inductor.

8. A control method for a conversion circuit compatible with AC and DC micro-electric energy input as claimed in claim 7, Features: When the energy stored in the inductor reaches a maximum value, the fifth low threshold transistor and the sixth low threshold transistor are turned off, and the rectifier circuit operates.

9. A control method for a conversion circuit compatible with AC and DC micro-electric energy input as claimed in claim 5, Features: The circuit working process when the AC input voltage of the conversion circuit is higher than the working voltage is as follows: When the input voltage of the conversion circuit is higher than the operating voltage, the fifth low threshold transistor and the sixth low threshold transistor stop working, and the rectification circuit takes over to rectify the input voltage.

10. A control method for a conversion circuit compatible with AC and DC micro-electric energy input as claimed in claim 2, Features: The PWM module adjusts the output PWM control signal according to the error signal of the error amplifier, thereby controlling the conversion circuit and adjusting the output voltage.

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