CN219039645U - Photovoltaic power optimizer start control circuit - Google Patents

Abstract

The utility model relates to the technical field of photovoltaic power optimizers, and particularly discloses a photovoltaic power optimizer starting control circuit, which comprises a power supply circuit and a low-power control circuit connected with the power supply circuit, wherein the low-power control circuit is used for judging the power value of an input end and controlling the power supply circuit to be conducted when the power value exceeds a threshold power and not started when the power value is lower than the threshold power; the low-power control circuit comprises a primary amplifying circuit, a secondary amplifying circuit and a voltage dividing circuit which are sequentially connected with a signal input end of the control chip. The signal at the signal input end is amplified through the primary amplifying circuit and the secondary amplifying circuit, so that the accuracy of power value detection is improved; meanwhile, the power of the input end is detected by controlling the triode through the analog circuit, the effect that the power supply circuit is not started when the voltage is low is achieved, the situation that the voltage is too low to cause repeated restarting is avoided, and the service life of the controller is prolonged.

Description

Photovoltaic power optimizer start control circuit

technical field

The utility model relates to the technical field of a photovoltaic power optimizer, in particular to a start-up control circuit of a photovoltaic power optimizer.

Background technique

Photovoltaic power optimizers are mainly used in photovoltaic power plants that use multiple photovoltaic modules connected in series and parallel. It is mainly to solve the problem that when there is a state difference between the components in the power station, or some components are blocked or damaged, the output power of the inverter will be reduced when some or all components are uniformly tracked to the maximum power point, resulting in low efficiency. Therefore, a maximum power optimizer is installed in each photovoltaic module to increase the output power.

In the process of using the photovoltaic power optimizer, we found that when the photovoltaic panels are blocked or the light conditions are weak in the morning and evening, the system will cause the circuit to restart repeatedly. This situation is mainly because the power supply voltage input from the photovoltaic panel to the photovoltaic power optimizer board is unstable, resulting in repeated restarts of the voltage out of control. The repeated restart of the circuit will cause the MCU chip to restart continuously, resulting in the internal memory of the chip being continuously erased and written, and the number of erasing and writing of the chip has a lifespan, which leads to a significant reduction in the service life of the chip, thereby reducing the life of the entire controller.

Therefore, in order to improve the service life of the controller and avoid the problem of repeated restarts of the circuit, it is now necessary to provide a photovoltaic power optimizer start-up control circuit.

Utility model content

The utility model intends to provide a start-up control circuit for a photovoltaic power optimizer, which solves the problem of repeated circuit restarts and reduced service life of chips.

In order to achieve the above object, the utility model adopts the following technical solutions:

The utility model is mainly used to avoid the problem of repeated restart of the circuit when the photovoltaic panel is blocked or the light is weak in the morning and evening, so as to improve the service life of the control chip, prolong the service life of the entire controller, improve the use efficiency, and reduce the cost of equipment replacement. Specifically, a photovoltaic power optimizer startup control circuit is provided, including a power supply circuit, and a low-power control circuit connected to the power supply circuit, the low-power control circuit is used to determine the input power value, and control the power supply circuit when the power value exceeds When the threshold power is turned on, it will not start when the power value is lower than the threshold power; the low power control circuit includes a primary amplifier circuit, a secondary amplifier circuit, and a voltage divider circuit that are sequentially connected to the signal input end of the control chip; The primary amplifier circuit includes a first voltage dividing resistor connected to the base terminal of the transistor Q2; the secondary amplifier circuit includes a power supply resistor connected to the collector terminal of the transistor Q1, and a bias resistor connected to the base terminal of the transistor Q1. The power supply resistor and the bias resistor are respectively connected to the power supply terminal; the voltage divider circuit includes a second voltage divider resistor, a diode cathode terminal and an enabling terminal respectively connected to the second voltage divider resistor, and the diode anode terminal is connected to the output terminal.

The principle and advantages of this scheme are:

Only when the power value exceeds the threshold power, the power supply terminal will start to work, so that the photovoltaic power optimizer can start to work normally, so as to ensure that the control chip of the optimizer will not be started to work when the power supply voltage output by the photovoltaic panel is low or unstable. In this way, repeated restarts are avoided, the service life of the control chip is ensured, and the service life of the controller is improved.

At the same time, the signal at the signal input terminal is amplified through the primary amplifier circuit and the secondary amplifier circuit to ensure that the signal is amplified as much as possible without distortion, so as to improve the accuracy of the signal, thereby improving the accuracy of power value detection , effectively improving the detection efficiency. At the same time, the output power value is detected to ensure the stability of the detection data and further improve the judgment accuracy. And through the characteristics of the triode switch, the power supply circuit is turned on or off, so as to achieve the effect of automatic control without starting at low power.

Further, the power supply resistor includes a resistor R7 and a resistor R6 respectively connected in parallel with the collector terminal of the triode Q1; the resistance value of the resistor R7 and the resistor R6 is 100Ω. Choose a resistor with a power resistance value around 100Ω to increase the power consumption of the power supply resistor, thereby reducing the voltage at the power supply terminal, ensuring that the output voltage is lower than the threshold voltage, avoiding false starts, and reducing repeated restarts.

Further, the bias resistor includes a resistor R8 and a resistor R9 respectively connected in parallel with the base terminal of the triode Q1; the resistance values of the resistor R8 and the resistor R9 are greater than 10KΩ. Select a resistor with a power resistance value above 10KΩ to ensure that the power consumption of the bias resistor is extremely small during normal operation, to ensure that the resistance will not affect the normal output of the voltage, to ensure the stability of the output voltage during operation, and to prevent the overvoltage during operation. If the change is too low, there will be continuous restarts.

Further, the first voltage dividing resistor includes a resistor R10 and a resistor R12 sequentially connected to the signal input terminal; one end of the resistor R12 is connected to the base terminal of the transistor Q2; the other end of the resistor R12 is connected to the transistor Q2 to transmit Extreme connection.

Further, the collector terminal of the triode Q2 is respectively connected to the base terminal of the triode Q1, one end of the resistor R8 and one end of the resistor R9; the other end of the resistor R8 is connected to the other end of the resistor R9, the other end of the resistor R6, the other end of the resistor R7, and the power supply terminal ; The emitter end of the transistor Q2 is connected to the emitter end of the transistor Q1; the emitter end of the transistor Q1 is grounded.

Further, the second voltage dividing resistor includes a resistor R5 and a resistor R11 sequentially connected to the other end of the resistor R7; the other end of the resistor R5 is respectively connected to the cathode end of the diode D1 and the enabling end; the anode end of the diode D1 is connected to the power supply terminal; the other terminal of the resistor R11 is respectively connected to one terminal of the capacitor C5 and grounded; the other terminal of the capacitor C5 is connected to the cathode terminal of the diode D1. After starting, the diode D1 is connected to the enable terminal, which can effectively avoid the abnormal situation that the power circuit restarts continuously due to low voltage during the working process, ensure the stable output of the power circuit, and effectively improve the service life of the controller.

Further, the power supply circuit is a 12V to 3.3V DC-DC power supply circuit; the power supply circuit includes a power supply chip, and one end of the resistor R1, one end of the resistor R4, and an enabling terminal respectively connected to the enable pin of the power chip; The other end of the resistor R1 is respectively connected to the power supply terminal and the input pin of the power chip; the pin 6 of the power chip is connected to the inductor L1 and the output terminal in turn.

Further, one end of the capacitor C1 is connected to the pin 1 of the power chip, and the other end of the capacitor C1 is connected to one end of the inductor L1.

Further, the pins 3 of the power chip are respectively connected to one end of the resistor R3 and one end of the resistor R2; the other end of the resistor R2 is respectively connected to the other end of the inductor L1, one end of the capacitor C3 and the power supply end.

Further, the other end of the resistor R4 is respectively connected to the pin 2 of the power chip, the other end of the resistor R3 and the other end of the capacitor C3; the pin 2 of the power chip is grounded.

Description of drawings

Fig. 1 is the structural representation of the utility model embodiment;

Fig. 2 is the circuit diagram of the low power control unit of the utility model embodiment;

Fig. 3 is a circuit diagram of a power supply unit according to an embodiment of the present invention.

Detailed ways

The following is further described in detail through specific implementation methods:

The reference signs in the drawings of the specification include: control chip 1 , low power control circuit 2 , power supply circuit 3 .

The embodiment is basically shown in Figure 1: the photovoltaic power optimizer startup control circuit is used to accurately determine the input power output from the photovoltaic panel to the photovoltaic power optimizer, to ensure that when the input power is too low, the control does not start the work in the optimizer circuit, so as to avoid the repeated restart of the circuit, effectively improve the service life of the optimizer control chip 1, thereby increasing the service life of the controller. Specifically, it includes a low-power control circuit 2 connected to a control chip 1 (MCU) through a signal input terminal Signal1, and a power supply circuit 3 connected to the low-power control circuit 2 . In this embodiment, the control chip 1 (MCU) adopts GD32F310K8T6 (Gigayi) chip.

Specifically, as shown in Figure 2, the low power control circuit 2 is used to determine whether the power input by the signal input terminal exceeds the threshold power, and after the threshold power is exceeded, the enabling terminal is turned on to start the power supply circuit 3 to make it work ; If the threshold power is not exceeded, the power supply circuit 3 is not started. Compared with judging the voltage in the circuit, judging the power value is more stable and accurate, so that it can better ensure the accuracy of judging low power in a small range and ensure the accuracy of judging. Specifically, the low-power control circuit 2 includes one end of a resistor R10 connected to the signal input terminal Signal1 of the control chip 1, and the other end of the resistor R10 is respectively connected to one end of the resistor R12 and the base end of the transistor Q2; the other end of the resistor R12 is connected to the transistor Q2. Extreme connection.

The collector terminal of the triode Q2 is respectively connected to the base terminal of the triode Q1, one end of the resistor R8 and one end of the resistor R9. In this embodiment, resistors R8 and R9 are selected with a power resistance value above 10KΩ, which consumes very little power during operation, which can ensure that the power consumed during circuit operation is minimized, thereby not affecting the circuit voltage and avoiding voltage drop. Circuit instability causes constant restarts, while effectively reducing energy consumption during normal operation. The collector terminal of the triode Q1 is respectively connected to one end of the resistor R7 and one end of the resistor R6, and the other end of the resistor R7 is respectively connected to the other end of the resistor R6, the other end of the resistor R8, the other end of the resistor R9, the power supply terminal VCC and one end of the resistor R5; The emitter end of the transistor Q1 is connected to the emitter end of the transistor Q2. In this embodiment, resistors R6 and R7 use resistors with a power resistance around 100Ω, and their power consumption is large. When processing and judging the output power in the circuit, the output power value can be effectively reduced, thereby ensuring low power and low Threshold power, to ensure that the precise control enable terminal is not turned on, so as to precisely control the power supply circuit 3 not to start at low power, reduce the situation of repeated startup under low power conditions, and also ensure that the power supply circuit 3 can be provided when starting work Sufficient and stable output power.

The other end of the resistor R5 is respectively connected to one end of the resistor R11, one end of the capacitor C5, the cathode end of the diode D1 and the enable end 3.3V_EN. The other end of the resistor R11 is connected to the other end of the capacitor C5 and the emitter end of the transistor Q1; the emitter end of the transistor Q1 is grounded. The anode of the diode D1 is connected to the output terminal 3.3V; the enable terminal 3.3V_EN is a judgment node between the output power and the threshold power, and the threshold power in this embodiment is 1.3W. Only when the output power exceeds the threshold power, the power supply circuit 3 will start, so as to ensure the stability of the power in the working state and avoid repeated restarts.

Concretely, as shown in accompanying drawing 3, described power supply circuit 3 is 12V to 3.3V DC-DC (the electric energy of one voltage value is changed into the electric energy of another voltage value in the DC circuit) power supply circuit, in the present embodiment is Convert the 12V voltage network of the photovoltaic power optimizer to a 3.3V voltage network. The power supply circuit 3 includes a power supply chip U1. In this embodiment, the power supply chip U1 is a power supply DCDC chip, which adopts an ETA2845S2G (Yutai) chip. And one end of resistor R1, one end of resistor R4 and the enable terminal 3.3V_EN respectively connected to the enable pin 4 (EN) of the power chip U1; the enable pin 4 of the power chip U1 is the activation pin of the power chip U1. After the power at terminal 3.3V_EN exceeds the threshold power of 1.3W, the pin will be activated, so that the power chip U1 will work, and then there will be power output. At the same time, a low-power control circuit 2 is designed around the enable pin 4 to realize various power-on functions of the power chip U1, so as to ensure that the power circuit 3 does not start when the power is low, and at the same time it will not affect the normal operation of the power chip U1 , greatly improve the efficiency of the power supply chip U1, save power consumption, prolong the service life of the power chip, thereby improving the service life of the entire controller power supply. The other end of the resistor R1 is respectively connected to the power supply terminal VCC and the input pin 5 (IN) of the power chip U1; the other end of the resistor R4 is connected to the pin 2 (GND) of the power chip U1, and the pin 2 of the power chip U1 is grounded , to ensure the stability and safety of the circuit.

Specifically, the pin 6 (LX) of the power chip U1 is respectively connected to one end of the capacitor C1 and one end of the inductor L1; the other end of the capacitor C1 is connected to the pin 1 of the power chip U1; the other end of the inductor L1 is respectively connected to one end of the resistor R2, One end of capacitor C3 and the output end 3.3V. After the output power exceeds the threshold power, the power supply circuit 3 converts the 12V voltage value into a 3.3V voltage that meets the working requirements and outputs it. The conversion efficiency is high, and the repeated restart of the voltage is avoided during operation, while ensuring the accuracy of the output voltage. Meet the needs of circuit work.

Specifically, the pin 3 (FB) of the power chip U1 is respectively connected to one end of the resistor R3 and one end of the resistor R2; the other end of the resistor R3 is connected to the pin 2 of the power chip U1. The other end of the resistor R2 is respectively connected to the other end of the inductor L1 and one end of the capacitor C3; the other end of the capacitor C3 is connected to the other end of the resistor R3.

The specific implementation process is as follows:

As shown in accompanying drawings 1 to 3, when the power output to the optimizer through the photovoltaic panel is 0 or lower, the power received by the control chip 1 of the optimizer through the signal input terminal Signal1 is 0 or lower, At this time, the base of the transistor Q2 is extremely low, the transistor Q2 works in the cut-off state, and the transistor Q1 works in the saturated state. At this time, the current passing through the resistor R6 and the resistor R7 will consume a certain amount of power. reduce. When the output power is low, the voltage of the power supply terminal VCC decreases, and the power at the enable terminal 3.3V_EN is lower than the threshold power, thereby controlling the enable terminal 3.3V_EN to be non-conductive, so that the power supply circuit 3 does not start to work. When the input power is large enough, the voltage of the power supply terminal VCC increases, and the voltage divided by the resistor R5 and the resistor R11 also increases accordingly. At this time, the power at the enable terminal 3.3V_EN exceeds the threshold power, and the enable terminal 3.3V_EN is turned on, so that the output terminal 3.3V can output normally, and then control the power supply circuit 3 to start to work normally.

At this time, when the output terminal 3.3V is normally output, the signal of the input pin Signal1 of the control chip 1 is high, the triode Q2 is turned on in the saturated state, the triode Q1 works in the cut-off state, the resistor R6 and the resistor R7 stop working, the resistor R8 and the resistor R9 works normally, and the output terminal 3.3V is directly connected to the enable terminal 3.3V_EN through the diode D1 to avoid backflow during operation, ensure the power stability of the enable terminal 3.3V_EN, and effectively prevent the power circuit 3 from restarting repeatedly.

In this embodiment, the power of the triode detection input terminal is controlled by the analog circuit, thereby controlling the working state of the power supply circuit 3 by controlling the conduction state of the enable pin of the power supply chip U1, so as to achieve the effect that the power supply circuit 3 does not start when the power is low, and then To achieve the effect of controlling the optimizer to control the chip not to start. Effectively reduce the abnormal situation that the circuit restarts repeatedly when the output power is too low or 0 when the photovoltaic panel is blocked or the light is insufficient. When the 12V voltage network of the photovoltaic power optimizer can stabilize the voltage at 7.62V with a 50Ω load, the photovoltaic power optimization will only be started when the power at the input terminal of the enable pin of the power chip U1 is not lower than the threshold power The normal operation of the optimizer ensures the stability of the power during operation, avoids repeated restarts caused by too low power, and effectively improves the use efficiency, thereby preventing the control chip 1 of the optimizer from being continuously erased by invalid restarts and effectively prolonging the service life of the control chip 1 , while prolonging the service life of the controller.

What is described above is only the embodiment of the utility model, and the specific technical solutions and/or characteristics and other general knowledge known in the solutions are not described here too much. It should be pointed out that for those skilled in the art, without departing from the technical solution of the utility model, some modifications and improvements can also be made, and these should also be regarded as the protection scope of the utility model, and these will not affect the utility model. Effects of utility model implementation and practicability of patents. The scope of protection required by this application shall be based on the content of the claims, and the specific implementation methods and other records in the specification may be used to interpret the content of the claims.

Claims (10)

1. Photovoltaic power optimizer start-up control circuit, it is characterized in that: comprise power circuit, and the low power control circuit that is connected with power circuit, described low power control circuit is used for judging the power value of input, and controls described power circuit in Conducting when the power value exceeds the threshold power, and not starting when the power value is lower than the threshold power; the low power control circuit includes a primary amplifier circuit, a secondary amplifier circuit, and a voltage divider circuit sequentially connected to the signal input terminal of the control chip ; The primary amplifier circuit includes a first voltage dividing resistor connected to the base terminal of the transistor Q2; the secondary amplifier circuit includes a power supply resistor connected to the collector terminal of the transistor Q1, and a bias resistor connected to the base terminal of the transistor Q1 , the power supply resistor and the bias resistor are respectively connected to the power supply terminal; the voltage divider circuit includes a second voltage divider resistor, a diode cathode terminal and an enabling terminal respectively connected to the second voltage divider resistor, and the diode anode terminal is connected to output. 2. The start-up control circuit of photovoltaic power optimizer according to claim 1, characterized in that: the power supply resistance comprises resistance R7 and resistance R6 connected in parallel with the collector terminal of triode Q1 respectively; The resistance value is 100Ω. 3. The photovoltaic power optimizer startup control circuit according to claim 2, characterized in that: the bias resistors include resistors R8 and R9 connected in parallel with the base terminals of the triode Q1 respectively; The resistance value is greater than 10KΩ. 4. The start-up control circuit of photovoltaic power optimizer according to claim 1, characterized in that: the first voltage dividing resistor comprises a resistor R10 and a resistor R12 which are sequentially connected to the signal input end; one end of the resistor R12 is connected to the The base terminal of the transistor Q2 is connected; the other end of the resistor R12 is connected with the emitter terminal of the transistor Q2. 5. The photovoltaic power optimizer startup control circuit according to claim 3, characterized in that: the collector terminal of the triode Q2 is respectively connected to the base terminal of the triode Q1, one end of the resistor R8 and one end of the resistor R9; the other end of the resistor R8 is respectively Connect the other end of the resistor R9, the other end of the resistor R6, the other end of the resistor R7, and the power supply; the emitter end of the transistor Q2 is connected to the emitter end of the transistor Q1; the emitter end of the transistor Q1 is grounded. 6. The photovoltaic power optimizer startup control circuit according to claim 2, characterized in that: the second voltage dividing resistor includes resistor R5 and resistor R11 connected to the other end of resistor R7 in sequence; the other end of resistor R5 is respectively Connect the cathode terminal of the diode D1 and the enabling terminal; the anode terminal of the diode D1 is connected to the power supply terminal; the other terminal of the resistor R11 is respectively connected to one terminal of the capacitor C5 and grounded; the other terminal of the capacitor C5 is connected to the cathode terminal of the diode D1. 7. The photovoltaic power optimizer startup control circuit according to claim 1, characterized in that: the power circuit is a 12V to 3.3V DC-DC power circuit; the power circuit includes a power chip, and is enabled with the power chip The pins are respectively connected to one end of the resistor R1, one end of the resistor R4 and the enable end; the other end of the resistor R1 is respectively connected to the power supply terminal and the input pin of the power chip; the pin 6 of the power chip is connected to the inductor L1 and the output terminal in turn. 8 . The start-up control circuit of the photovoltaic power optimizer according to claim 7 , wherein the pin 1 of the power chip is connected to one end of a capacitor C1 , and the other end of the capacitor C1 is connected to one end of an inductor L1 . 9. The start-up control circuit of the photovoltaic power optimizer according to claim 8, characterized in that: the pins 3 of the power chip are respectively connected to one end of the resistor R3 and one end of the resistor R2; the other end of the resistor R2 is respectively connected to the other end of the inductor L1 , one end of capacitor C3 and the power supply end. 10. The photovoltaic power optimizer startup control circuit according to claim 9, characterized in that: the other end of the resistor R4 is respectively connected to the power chip pin 2, the other end of the resistor R3 and the other end of the capacitor C3; Pin 2 is grounded.

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