Anti-PID circuit and photovoltaic system

Abstract

The embodiment of the utility model provides an anti-PID circuit and a photovoltaic system. The anti-PID circuit comprises a DC conversion unit, a boost unit, a sampling feedback unit and a current-limiting resistor. The input end of the DC conversion unit is connected with a power supply, and the output end is connected with the input end of the boost unit. A first output end of the boost unit is connected with the photovoltaic module, and a second output end is grounded through a current-limiting resistor; a first input end of the sampling feedback unit is connected with a first output end of the boost unit, a second input end and a third input end are connected with two ends of the current-limiting resistor, and an output end of the sampling feedback unit is connected with an input end of the DC conversion unit. The turn ratio of the transformer is adjusted through the boosting unit, voltage in a wide range is output when input voltage is low, and the power supply conversion efficiency is improved. The sampling feedback unit adjusts the output voltage of the DC conversion unit in real time according to the acquired voltage to ground of the photovoltaic module, thereby realizing control of the output voltage of the DC conversion unit and preventing PID effect.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic systems, in particular to an anti-PID circuit and a photovoltaic system. Background Art

[0002] Humid and high temperature environments will cause water vapor to be generated. In photovoltaic power generation systems, if water vapor penetrates into the interior of photovoltaic modules, the conductivity of the encapsulation material (ENC) will increase, resulting in an increase in the leakage current of the module. This will cause polarization on the surface of the photovoltaic module, resulting in a potential induced degradation (PID) effect. The PID effect refers to the phenomenon that the performance of the module is attenuated due to ion migration under the action of high voltage between the encapsulation material of the photovoltaic cell module and the materials on its upper and lower surfaces, and between the cell and its grounded metal frame. In order to reduce the attenuation of module performance, a PID power supply is usually connected in series between the negative pole of the photovoltaic module and the ground to raise the voltage of the negative pole of the photovoltaic module to the ground to achieve daytime protection and nighttime repair of the module PID effect.

[0003] In the related art, the PID power supply obtains the input voltage of the subsequent BOOST boost circuit through the conversion of the previous AC / DC switching power supply, and the subsequent stage then boosts the input voltage through the BOOST boost circuit to obtain the output voltage of the DC high-voltage power supply.

[0004] Since the photovoltaic system requires a wide range of output voltages for the DC high-voltage power supply, and the boost multiples of the BOOST boost circuit are limited, this will lead to higher input voltage requirements for the subsequent stage, and higher performance switching devices and diodes need to be selected in the BOOST boost circuit, which increases the cost of the photovoltaic system. Utility Model Content

[0005] In view of this, the embodiments of the present utility model provide an anti-PID circuit and a photovoltaic system, aiming to solve the problem of high cost of DC high voltage power supply in the photovoltaic system.

[0006] In a first aspect, an embodiment of the utility model provides an anti-PID circuit. The anti-PID circuit includes a DC conversion unit, a boost unit, a sampling feedback unit and a current limiting resistor;

[0007] The input end of the DC conversion unit is connected to the power supply, and the output end of the DC conversion unit is connected to the input end of the boost unit;

[0008] The first output end of the boost unit is connected to the photovoltaic module, and the second output end of the boost unit is grounded through the current limiting resistor;

[0009] The first input end of the sampling feedback unit is connected to the first output end of the boost unit, the second input end of the sampling feedback unit is connected to the first end of the current limiting resistor, the third input end of the sampling feedback unit is connected to the second end of the current limiting resistor, and the output end of the sampling feedback unit is connected to the input end of the DC conversion unit.

[0010] In a possible implementation, the DC conversion unit includes a first switch tube, a first diode, a first inductor and a first capacitor;

[0011] The first end of the first switch tube is connected to the power supply, the second end of the first switch tube is connected to the cathode of the first diode and the first end of the first inductor, the first end of the first switch tube is connected to the output end of the sampling feedback unit, the anode of the first diode is connected to the first end of the first capacitor and grounded, the second end of the first capacitor is connected to the second end of the first inductor, and the two ends of the first capacitor are connected to the input end of the boost unit.

[0012] In a possible implementation, the boost unit is a full-bridge topology circuit.

[0013] In a possible implementation, the full-bridge topology circuit includes a second switch tube, a third switch tube, a fourth switch tube, a fifth switch tube, a second diode, a third diode, a second inductor, a second capacitor and a first resistor;

[0014] The first end of the second switch tube is connected to the positive electrode of the output end of the DC conversion unit and the first end of the fourth switch tube, the second end of the second switch tube is connected to the first end of the third switch tube, and is connected to the second end of the fourth switch tube through the primary winding of the transformer;

[0015] The second end of the third switch tube is connected to the negative electrode of the output end of the DC conversion unit and the second end of the fifth switch tube;

[0016] The first end of the fifth switch tube is connected to the second end of the fourth switch tube, and the second end of the fifth switch tube is grounded;

[0017] The anode of the second diode is connected to the anode of the third diode through the secondary winding of the transformer, the cathode of the second diode and the cathode of the third diode are connected to one end of the second inductor, the other end of the second inductor is connected to one end of the second capacitor and the photovoltaic component, the other end of the second capacitor is connected to the secondary winding of the transformer and the first end of the current limiting resistor, the second end of the current limiting resistor is connected to the ground, and the first resistor is connected in parallel to the two ends of the second capacitor.

[0018] In a possible implementation, the boost unit is a half-bridge topology circuit.

[0019] In a possible implementation, the half-bridge topology circuit includes a sixth switch tube, a seventh switch tube, a third capacitor, a fourth capacitor, a fifth capacitor, a fourth diode, a fifth diode, a third inductor and a second resistor;

[0020] The first end of the fourth capacitor is connected to the positive electrode of the output end of the DC conversion unit and the first end of the sixth switch tube, the second end of the fourth capacitor is connected to the first end of the fifth capacitor, and is connected to the second end of the sixth switch tube through the primary winding of the transformer;

[0021] The second end of the fifth capacitor is connected to the negative electrode of the output end of the DC conversion unit and the second end of the seventh switch tube;

[0022] The first end of the seventh switch tube is connected to the second end of the sixth switch tube, and the second end of the seventh switch tube is grounded;

[0023] The anode of the fourth diode is connected to the anode of the fifth diode through the secondary winding of the transformer, the cathode of the fourth diode and the cathode of the fifth diode are connected to one end of the third inductor, the other end of the third inductor is connected to one end of the third capacitor and the photovoltaic component, the other end of the third capacitor is connected to the secondary winding of the transformer and the first end of the current limiting resistor, the second end of the current limiting resistor is connected to the ground, and the second resistor is connected in parallel to both ends of the third capacitor.

[0024] In a possible implementation manner, the boost unit is a push-pull topology circuit.

[0025] In a possible implementation, the push-pull topology circuit includes a sixth capacitor, a seventh capacitor, an eighth switch tube, a ninth switch tube, a sixth diode, a seventh diode, a fourth inductor and a third resistor;

[0026] One end of the seventh capacitor is connected to the positive electrode of the output end of the DC conversion unit and the primary winding of the transformer, and the other end is connected to the negative electrode of the output end of the DC conversion unit and grounded;

[0027] The first end of the eighth switch tube is connected to the first end of the ninth switch tube through the primary winding of the transformer, and the second end of the eighth switch tube is grounded;

[0028] The second end of the ninth switch tube is grounded;

[0029] The anode of the sixth diode is connected to the anode of the seventh diode through the secondary winding of the transformer, the cathode of the sixth diode and the cathode of the seventh diode are connected to one end of the fourth inductor, the other end of the fourth inductor is connected to one end of the sixth capacitor and the photovoltaic component, the other end of the sixth capacitor is connected to the secondary winding of the transformer and the first end of the current limiting resistor, the second end of the current limiting resistor is connected to the ground, and the third resistor is connected in parallel to both ends of the sixth capacitor.

[0030] In a possible implementation, the sampling feedback unit includes a comparator;

[0031] The first input terminal of the comparator is used to input a reference voltage, the second input terminal of the comparator is connected to the first output terminal of the boost unit; the output terminal of the comparator is connected to the input terminal of the DC conversion unit.

[0032] In a possible implementation, the sampling feedback unit includes a comparator;

[0033] The first input end of the comparator is connected to the first end of the current limiting resistor, the second input end of the comparator is connected to the second end of the current limiting resistor, and the output end of the comparator is connected to the input end of the DC conversion unit.

[0034] In a possible implementation, when the photovoltaic component is a P-type photovoltaic component, the first output end of the boost unit is connected to the negative pole of the photovoltaic component; when the photovoltaic component is an N-type photovoltaic component, the first output end of the boost unit is connected to the positive pole of the photovoltaic component.

[0035] In a second aspect, an embodiment of the utility model provides a photovoltaic system, including a photovoltaic module and an anti-PID circuit as described in any one of the first aspects above;

[0036] The output end of the anti-PID circuit is connected to the photovoltaic component, and two poles of the photovoltaic component are grounded through a fourth resistor and a fifth resistor respectively.

[0037] The embodiment of the utility model provides an anti-PID circuit and a photovoltaic system, the anti-PID circuit includes a DC conversion unit, a boost unit, a sampling feedback unit and a current limiting resistor; the input end of the DC conversion unit is connected to the power supply, and the output end of the DC conversion unit is connected to the input end of the boost unit; the first output end of the boost unit is connected to the photovoltaic module, and the second output end is grounded through the current limiting resistor; the first input end of the sampling feedback unit is connected to the first output end of the boost unit, the second input end is connected to the first end of the current limiting resistor, the third input end is connected to the second end of the current limiting resistor, and the output end of the sampling feedback unit is connected to the input end of the DC conversion unit. By adjusting the turns ratio of the transformer through the boost unit, a wider range of voltages can be output when the input voltage is low, thereby improving the power conversion efficiency. In addition, the sampling feedback unit can adjust the output voltage of the DC conversion unit in real time according to the collected voltage to ground of the photovoltaic module, thereby controlling the output voltage of the DC conversion unit and preventing the PID effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in this embodiment or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 A schematic diagram of an anti-PID circuit provided by an embodiment of the utility model;

[0040] Figure 2 A schematic diagram of a DC conversion unit provided in an embodiment of the utility model;

[0041] Figure 3 A schematic diagram of a full-bridge topology circuit provided by an embodiment of the utility model;

[0042] Figure 4 A schematic diagram of a half-bridge topology circuit provided by an embodiment of the utility model;

[0043] Figure 5 A schematic diagram of a push-pull topology circuit provided by an embodiment of the utility model;

[0044] Figure 6 A schematic diagram of a sampling feedback unit provided in an embodiment of the utility model;

[0045] Figure 7 A schematic diagram of a photovoltaic system provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0046] In the related art, the photovoltaic system has a wide range of output voltage requirements for the PID power supply, while the boost multiple of the BOOST boost circuit is limited. This will lead to higher input voltage requirements for the subsequent stage, and higher performance switching devices and diodes need to be selected in the BOOST boost circuit, which increases the cost of the photovoltaic system. In addition, the extreme boost multiple will cause very large losses to the components in the BOOST boost circuit.

[0047] There is also a related technology that uses multiple BOOST boost circuits to cascade boost to provide a wider range of output voltages. However, this will make the circuit more complicated and the reliability and output voltage stability worse.

[0048] In view of the technical problems existing in the above-mentioned prior art, the utility model provides an anti-PID circuit and a photovoltaic system, wherein the anti-PID circuit comprises a DC conversion unit, a boost unit, a sampling feedback unit and a current limiting resistor. The sampling feedback unit is used to collect the ground voltage of the photovoltaic module, and then the DC feedback unit and the boost unit are adjusted to realize closed-loop feedback. The output is stabilized near the set value, and the stability and accuracy of the voltage output are improved.

[0049] And by adjusting the boost multiple of the boost unit, the anti-PID circuit can output a wider range of voltage to meet the needs of PID power supply in the photovoltaic system.

[0050] Obviously, the embodiments described in the present invention are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0051] See also Figure 1 , Figure 1 A schematic diagram of an anti-PID circuit provided by an embodiment of the utility model. The PID power supply includes a DC conversion unit, a boost unit, a sampling feedback unit and a current limiting resistor Rt.

[0052] The input end of the DC conversion unit is connected to the power supply Vin, and the output end of the DC conversion unit is connected to the input end of the boost unit;

[0053] The first output end of the boost unit is connected to the photovoltaic module, and the second output end of the boost unit is grounded through the current limiting resistor Rt;

[0054] The first input end of the sampling feedback unit is connected to the first output end of the boost unit, the second input end of the sampling feedback unit is connected to the first end of the current limiting resistor Rt, the third input end of the sampling feedback unit is connected to the second end of the current limiting resistor Rt, and the output end of the sampling feedback unit is connected to the input end of the DC conversion unit.

[0055] In the embodiment of the utility model, the photovoltaic module can be a P-type photovoltaic module or an N-type photovoltaic module. When the photovoltaic module is a P-type photovoltaic module, the first output end of the boost unit is connected to the negative electrode of the photovoltaic module; when the photovoltaic module is an N-type photovoltaic module, the first output end of the boost unit is connected to the positive electrode of the photovoltaic module. The anti-PID circuit of the embodiment of the utility model is described by taking the photovoltaic module as a P-type photovoltaic module as an example.

[0056] The DC conversion unit can convert the input AC signal into a stable DC signal, reducing the impact of noise interference. This helps to improve the signal-to-noise ratio and overall performance of the system. The DC conversion unit can accurately adjust and control the input voltage as needed. The DC conversion unit usually has a high conversion efficiency and can minimize energy loss. This helps to improve the energy utilization of the entire power supply system.

[0057] In the anti-PID circuit provided by the utility model, the use of the DC conversion unit as the front-stage input of the boost circuit can provide a stable, accurate and efficient power output and reduce the influence of noise interference, which helps to improve system performance and reliability.

[0058] The boost unit can be used to increase the voltage output by the DC conversion unit to the output voltage level required by the photovoltaic system, that is, the output voltage Upid of the boost unit, so as to ensure that the photovoltaic system obtains a stable voltage supply during operation, thereby repairing the PID effect. In addition, the boost unit can provide a higher multiple of the output voltage, thereby meeting the photovoltaic system's demand for PID power supply.

[0059] The sampling feedback unit obtains the voltage of the photovoltaic module to the ground by sampling the output voltage of the boost unit. The sampling feedback unit can detect the changes in the output voltage and the voltage of the photovoltaic module to the ground in a timely manner, and adjust the output of the DC conversion unit as needed to achieve stable control of the output voltage. This enables the system to adjust the input according to the actual output situation, thereby achieving closed-loop control. This closed-loop control can be adjusted according to real-time feedback to cope with the impact of different factors on the output voltage.

[0060] In a possible implementation, the structure of the DC conversion unit can be as follows: Figure 2 The DC conversion unit includes a first switch tube S1, a first diode D1, a first inductor L1 and a first capacitor C1;

[0061] A first end of the first switch tube S1 is connected to the power supply Vin, a second end of the first switch tube S1 is connected to the cathode of the first diode D1 and the first end of the first inductor L1, a control end of the first switch tube S1 is connected to the output end of the sampling feedback unit, an anode of the first diode D1 is connected to the first end of the first capacitor C1 and grounded, a second end of the first capacitor C1 is connected to the second end of the first inductor L1, and both ends of the first capacitor C1 are connected to the input end of the boost unit.

[0062] The output voltage Um of the DC conversion unit is the input voltage of the boost unit. The DC conversion unit controls the conduction state of the first switch tube S1 and uses the resonant circuit of the first inductor L1 and the first capacitor C1 to achieve energy storage and output, and finally transmits the stable output voltage Um to the boost unit for further boost processing. In this way, the voltage output of the system can be ensured to be stable and reliable.

[0063] In a possible implementation, the boost unit is a full-bridge topology circuit. The full-bridge topology circuit can quickly respond to load changes and maintain the stability of the output voltage by quickly switching the switch device. It has a fast dynamic response characteristic, can quickly adjust the output voltage to adapt to load changes, and reduce the fluctuation of the output voltage.

[0064] In one possible implementation, the structure of the full-bridge topology circuit is as follows: Figure 3 The full-bridge topology circuit includes a second switch tube S2, a third switch tube S3, a fourth switch tube S4, a fifth switch tube S5, a second diode D2, a third diode D3, a second inductor L2, a second capacitor C2 and a first resistor R1;

[0065] A first end of the second switch tube S2 is connected to the positive electrode of the output end of the DC conversion unit and a first end of the fourth switch tube S4, a second end of the second switch tube S2 is connected to a first end of the third switch tube S3, and is connected to a second end of the fourth switch tube S4 through a primary winding of a transformer;

[0066] The second end of the third switch tube S3 is connected to the negative electrode of the output end of the DC conversion unit and the second end of the fifth switch tube S5;

[0067] A first end of the fifth switch tube S5 is connected to a second end of the fourth switch tube S4, and a second end of the fifth switch tube S5 is grounded;

[0068] The anode of the second diode D2 is connected to the anode of the third diode D3 through the secondary winding of the transformer, the cathode of the second diode D2 and the cathode of the third diode D3 are connected to one end of the second inductor L2, the other end of the second inductor L2 is connected to one end of the second capacitor C2, the other end of the second capacitor C2 is connected to the secondary winding of the transformer, the two ends of the second capacitor C2 are respectively connected to the photovoltaic module and the first end of the current limiting resistor Rt, the second end of the current limiting resistor Rt is connected to the ground, and the first resistor R1 is connected in parallel to the two ends of the second capacitor C2. In the embodiment of the utility model, the photovoltaic module is a P-type photovoltaic module, so the two ends of the second capacitor C2 are respectively connected to the negative electrode of the P-type photovoltaic module and the first end of the current limiting resistor Rt.

[0069] The full-bridge topology circuit realizes energy storage, conversion and output through the joint operation of the second switch tube S2, the third switch tube S3, the fourth switch tube S4, the fifth switch tube S5, the second diode D2, the third diode D3, the second inductor L2 and the second capacitor C2, thereby achieving efficient voltage conversion and stable output.

[0070] Figure 3 The first resistor R1 in the figure is a dummy load, which refers to a resistor load used when performing a simulated load test on a power supply, and is used to test the power supply's output load capacity, stability, efficiency and other performance indicators. By connecting the first resistor R1 in parallel across the second capacitor C2, the power supply performance under real load conditions can be simulated to facilitate system testing and performance evaluation.

[0071] In a possible implementation, the boost unit is a half-bridge topology circuit. Selecting a half-bridge topology circuit as the boost unit in the anti-PID circuit can reduce costs, improve efficiency, simplify control, and improve response speed.

[0072] In a possible implementation, the structure of the half-bridge topology circuit can be as follows: Figure 4 The half-bridge topology circuit includes a sixth switch tube S6, a seventh switch tube S7, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a fourth diode D4, a fifth diode D5, a third inductor L3 and a second resistor R2;

[0073] A first end of the fourth capacitor C4 is connected to the positive electrode of the output end of the DC conversion unit and the first end of the sixth switch tube S6, a second end of the fourth capacitor C4 is connected to the first end of the fifth capacitor C5, and is connected to the second end of the sixth switch tube S6 through the primary winding of the transformer;

[0074] The second end of the fifth capacitor C5 is connected to the negative electrode of the output end of the DC conversion unit and the second end of the seventh switch tube S7;

[0075] The first end of the seventh switch tube S7 is connected to the second end of the sixth switch tube S6, and the second end of the seventh switch tube S7 is grounded;

[0076] The anode of the fourth diode D4 is connected to the anode of the fifth diode D5 through the secondary winding of the transformer, the cathode of the fourth diode D4 and the cathode of the fifth diode D5 are connected to one end of the third inductor L3, the other end of the third inductor L3 is connected to one end of the third capacitor C3 and the photovoltaic module, the other end of the third capacitor C3 is connected to the secondary winding of the transformer and the first end of the current limiting resistor Rt, the second end of the current limiting resistor Rt is connected to the ground, and the second resistor R2 is connected in parallel to the two ends of the third capacitor C3. In the embodiment of the utility model, the photovoltaic module is a P-type photovoltaic module, so the two ends of the third capacitor C3 are respectively connected to the negative electrode of the P-type photovoltaic module and the first end of the current limiting resistor Rt.

[0077] The half-bridge topology circuit realizes energy storage, conversion and output through the joint operation of the sixth switch tube S6, the seventh switch tube S7, the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, the fourth diode D4, the fifth diode D5 and the third inductor L3, thereby realizing efficient voltage boost, voltage reduction or voltage conversion functions.

[0078] Figure 4 The second resistor R2 in the circuit is also a dummy load and has the same function as Figure 3 The first resistor R1 is the same as that in FIG. 1 and will not be described in detail here.

[0079] In a possible implementation, the boost unit is a push-pull topology circuit. The push-pull topology circuit can achieve efficient energy conversion because it can reduce the energy loss during the on and off process of the switch device. Since the push-pull topology circuit is composed of two alternately switched devices, the voltage pressure and power loss of each switch device are relatively low.

[0080] In a possible implementation, the structure of the push-pull topology circuit can be as follows: Figure 5 The push-pull topology circuit includes a sixth capacitor C6, a seventh capacitor C7, an eighth switch tube S8, a ninth switch tube S9, a sixth diode D6, a seventh diode D7, a fourth inductor L4 and a third resistor R3;

[0081] One end of the seventh capacitor C7 is connected to the positive electrode of the output end of the DC conversion unit and the primary winding of the transformer, and the other end is connected to the negative electrode of the output end of the DC conversion unit and grounded;

[0082] A first end of the eighth switch tube S8 is connected to a first end of the ninth switch tube S9 through the primary winding of the transformer, and a second end of the eighth switch tube S8 is grounded;

[0083] The second end of the ninth switch tube S9 is grounded;

[0084] The anode of the sixth diode D6 is connected to the anode of the seventh diode D7 through the secondary winding of the transformer, the cathode of the sixth diode D6 and the cathode of the seventh diode D7 are connected to one end of the fourth inductor L4, the other end of the fourth inductor L4 is connected to one end of the sixth capacitor C6 and the photovoltaic module, the other end of the sixth capacitor C6 is connected to the secondary winding of the transformer and the first end of the current limiting resistor Rt, the second end of the current limiting resistor Rt is connected to the ground, and the third resistor R3 is connected in parallel to the two ends of the sixth capacitor C6. In the embodiment of the utility model, the photovoltaic module is a P-type photovoltaic module, so the two ends of the sixth capacitor C6 are respectively connected to the negative electrode of the P-type photovoltaic module and the first end of the current limiting resistor Rt.

[0085] The boost multiple of the push-pull boost circuit can be set by the transformer turns ratio to achieve the wide range of output voltage required by the PID power supply.

[0086] Figure 5 The third resistor R3 in the circuit is also a dummy load and has the same function as Figure 3 The first resistor R1 and Figure 4 The second resistor R2 is the same as that in FIG. 1 and will not be described in detail here.

[0087] In a possible implementation, the structure of the sampling feedback unit can be as follows: Figure 6 The sampling feedback unit includes a comparator;

[0088] The first input terminal of the comparator is used to input a reference voltage, the second input terminal of the comparator is connected to the first output terminal of the boost unit, and the output terminal of the comparator is connected to the input terminal of the DC conversion unit.

[0089] The voltage is sampled according to the sampling feedback unit, and the voltage of the photovoltaic module to the ground is acquired by the second input terminal of the comparator. The output voltage of the DC conversion circuit is adjusted according to the real-time acquired voltage to the ground, and then an adjustable wide-range PID power supply voltage is output through the boost unit. The voltage output terminal of the anti-PID circuit is connected to the photovoltaic module, so as to suppress and repair the PID effect of the photovoltaic module.

[0090] In another possible implementation, Figure 6 In the sampling feedback unit, the first input end of the comparator is connected to the first end of the current limiting resistor, the second input end of the comparator is connected to the second end of the current limiting resistor, and the output end of the comparator is connected to the input end of the DC conversion unit.

[0091] The voltage is sampled according to the sampling feedback unit, and the voltage of the current limiting resistor Rt to ground is acquired by using the first input terminal and the second input terminal of the comparator. The output voltage of the DC conversion circuit is adjusted according to the real-time acquired voltage to ground, and then an adjustable wide-range PID power supply voltage is output through the boost unit. The voltage output terminal of the anti-PID circuit is connected to the photovoltaic module, so as to suppress and repair the PID effect of the photovoltaic module.

[0092] In an embodiment of the utility model, a photovoltaic system is also provided, including a photovoltaic module and an anti-PID circuit as described in any one of the above embodiments;

[0093] The output end of the anti-PID circuit is connected to the photovoltaic module, and the two poles of the photovoltaic module are grounded through the fourth resistor R4 and the fifth resistor R5 respectively. In the embodiment of the utility model, the photovoltaic module is a P-type photovoltaic module, so the negative pole PV- of the P-type photovoltaic module is connected to the ground through the fourth resistor R4, and the positive pole PV+ is connected to the ground through the fifth resistor R5.

[0094] The "first" and "second" in the names such as "first" and "second" (if any) mentioned in the embodiments of the present invention are only used as name identifications and do not represent the first or second in order.

[0095] Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. Some or all of the modules can be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative work.

[0096] The above description is merely an exemplary embodiment of the present invention and is not intended to limit the protection scope of the present invention.

Claims

1. A PID prevention circuit, characterized in that: It includes a DC conversion unit, a boost unit, a sampling feedback unit and a current limiting resistor; The input end of the DC conversion unit is connected to the power supply, and the output end of the DC conversion unit is connected to the input end of the boost unit; The first output end of the boost unit is connected to the photovoltaic module, and the second output end of the boost unit is grounded through the current limiting resistor; The first input end of the sampling feedback unit is connected to the first output end of the boost unit, the second input end of the sampling feedback unit is connected to the first end of the current limiting resistor, the third input end of the sampling feedback unit is connected to the second end of the current limiting resistor, and the output end of the sampling feedback unit is connected to the input end of the DC conversion unit.

2. The circuit according to claim 1, characterized in that The DC conversion unit includes a first switch tube, a first diode, a first inductor and a first capacitor; The first end of the first switch tube is connected to the power supply, the second end of the first switch tube is connected to the cathode of the first diode and the first end of the first inductor, the control end of the first switch tube is connected to the output end of the sampling feedback unit, the anode of the first diode is connected to the first end of the first capacitor and grounded, the second end of the first capacitor is connected to the second end of the first inductor, and the two ends of the first capacitor are connected to the input end of the boost unit.

3. The circuit according to claim 1, characterized in that The boost unit is a full-bridge topology circuit.

4. The circuit according to claim 3, characterized in that The full-bridge topology circuit includes a second switch tube, a third switch tube, a fourth switch tube, a fifth switch tube, a second diode, a third diode, a second inductor, a second capacitor and a first resistor; The first end of the second switch tube is connected to the positive electrode of the output end of the DC conversion unit and the first end of the fourth switch tube, the second end of the second switch tube is connected to the first end of the third switch tube, and is connected to the second end of the fourth switch tube through the primary winding of the transformer; The second end of the third switch tube is connected to the negative electrode of the output end of the DC conversion unit and the second end of the fifth switch tube; The first end of the fifth switch tube is connected to the second end of the fourth switch tube, and the second end of the fifth switch tube is grounded; The anode of the second diode is connected to the anode of the third diode through the secondary winding of the transformer, the cathode of the second diode and the cathode of the third diode are connected to one end of the second inductor, the other end of the second inductor is connected to one end of the second capacitor and the photovoltaic component, the other end of the second capacitor is connected to the secondary winding of the transformer and the first end of the current limiting resistor, the second end of the current limiting resistor is connected to the ground, and the first resistor is connected in parallel to the two ends of the second capacitor.

5. The circuit according to claim 1, characterized in that The boost unit is a half-bridge topology circuit.

6. The circuit according to claim 5, characterized in that The half-bridge topology circuit includes a sixth switch tube, a seventh switch tube, a third capacitor, a fourth capacitor, a fifth capacitor, a fourth diode, a fifth diode, a third inductor and a second resistor; The first end of the fourth capacitor is connected to the positive electrode of the output end of the DC conversion unit and the first end of the sixth switch tube, the second end of the fourth capacitor is connected to the first end of the fifth capacitor, and is connected to the second end of the sixth switch tube through the primary winding of the transformer; The second end of the fifth capacitor is connected to the negative electrode of the output end of the DC conversion unit and the second end of the seventh switch tube; The first end of the seventh switch tube is connected to the second end of the sixth switch tube, and the second end of the seventh switch tube is grounded; The anode of the fourth diode is connected to the anode of the fifth diode through the secondary winding of the transformer, the cathode of the fourth diode and the cathode of the fifth diode are connected to one end of the third inductor, the other end of the third inductor is connected to one end of the third capacitor and the photovoltaic component, the other end of the third capacitor is connected to the secondary winding of the transformer and the first end of the current limiting resistor, the second end of the current limiting resistor is connected to the ground, and the second resistor is connected in parallel to both ends of the third capacitor.

7. The circuit according to claim 1, characterized in that The boost unit is a push-pull topology circuit.

8. The circuit according to claim 7, characterized in that The push-pull topology circuit includes a sixth capacitor, a seventh capacitor, an eighth switch tube, a ninth switch tube, a sixth diode, a seventh diode, a fourth inductor and a third resistor; One end of the seventh capacitor is connected to the positive electrode of the output end of the DC conversion unit and the primary winding of the transformer, and the other end is connected to the negative electrode of the output end of the DC conversion unit and grounded; The first end of the eighth switch tube is connected to the first end of the ninth switch tube through the primary winding of the transformer, and the second end of the eighth switch tube is grounded; The second end of the ninth switch tube is grounded; The anode of the sixth diode is connected to the anode of the seventh diode through the secondary winding of the transformer, the cathode of the sixth diode and the cathode of the seventh diode are connected to one end of the fourth inductor, the other end of the fourth inductor is connected to one end of the sixth capacitor and the photovoltaic component, the other end of the sixth capacitor is connected to the secondary winding of the transformer and the first end of the current limiting resistor, the second end of the current limiting resistor is connected to the ground, and the third resistor is connected in parallel to both ends of the sixth capacitor.

9. The circuit according to claim 1, characterized in that The sampling feedback unit includes a comparator; The first input terminal of the comparator is used to input a reference voltage, the second input terminal of the comparator is connected to the first output terminal of the boost unit; the output terminal of the comparator is connected to the input terminal of the DC conversion unit.

10. The circuit according to claim 1, characterized in that The sampling feedback unit includes a comparator; The first input end of the comparator is connected to the first end of the current limiting resistor, the second input end of the comparator is connected to the second end of the current limiting resistor, and the output end of the comparator is connected to the input end of the DC conversion unit.

11. The circuit according to claim 1, characterized in that When the photovoltaic module is a P-type photovoltaic module, the first output end of the boost unit is connected to the negative electrode of the photovoltaic module; when the photovoltaic module is an N-type photovoltaic module, the first output end of the boost unit is connected to the positive electrode of the photovoltaic module.

12. A photovoltaic system, characterized in that: A photovoltaic module and an anti-PID circuit according to any one of claims 1 to 11; The output end of the anti-PID circuit is connected to the photovoltaic component, and two poles of the photovoltaic component are grounded through a fourth resistor and a fifth resistor respectively.

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