Mobile storage inverter module output short circuit protection circuit
By designing a short -circuit protection circuit for the inverter module, the throughput and comparison of the op amp and the diode group can be used to solve the problem of the output current limit of the inverter module in the existing technology. Safety and reliability.
Patent Information
- Application Number
- CN202420656658.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-01
- Publication Date
- 2025-01-24
- Estimated Expiration
- 2034-04-01
AI Technical Summary
The prior art is difficult to quickly and effectively limit the output current of the inverter module, especially in short circuit or overload conditions, which may cause damage to the inverter module or endanger personal safety.
A kind of output short-circuit protection circuit of the storage inverter module is designed. It is connected to the reverse and forward input terminals of the op amp through the input terminal, and current sampling and comparison is realized through the resistor and diode group. The MCU is used to control the PWM signal and quickly limit it. output current.
A fast limit output current is achieved, avoiding damage to the inverter module caused by short -circuit or overloading, improves the security and reliability of the system, the response speed is fast, and the working principle is simple and reliable.
Smart Images
Figure CN222395446U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of power electronics, in particular to an output short-circuit protection circuit of a transfer-storage inverter module. Background Art
[0002] With the development of outdoor electronic products, the demand for energy storage mobile power supplies is increasing. In the past two years, bidirectional charging and discharging AC / DC converters have been promoted. Outdoor portable power supplies convert batteries into AC output through inverters to meet the needs of various daily electronic products. As a civilian consumer product, its safety and reliability are highly valued. In daily use by consumers, overload and short circuit may occur. Summary of the invention
[0003] The technical problem to be solved by the utility model is to provide a transfer storage inverter module output short-circuit protection circuit, which can solve the deficiencies of the prior art, can output overload short-circuit protection, and quickly limit the output current.
[0004] In order to solve the above technical problems, the technical solutions adopted by the present utility model are as follows.
[0005] A short-circuit protection circuit for output of a shift-storage inverter module, wherein input ends are respectively connected to a reverse input end of a first operational amplifier and a forward input end of a second operational amplifier, the forward input end of the first operational amplifier is connected to an MCU end through a first resistor, the forward input end of the first operational amplifier is grounded through a second resistor, the reverse input end of the second operational amplifier is connected to the MCU end through a third resistor, the reverse input end of the second operational amplifier is grounded through a fourth resistor, the output ends of the first operational amplifier and the second operational amplifier are connected to the output end of the third operational amplifier, the forward input end of the third operational amplifier is connected to the MCU end through a fifth resistor, the forward input end of the third operational amplifier is connected to the output end of the third operational amplifier through a sixth resistor, a first capacitor is connected between the forward input end of the third operational amplifier and the reverse input end of the third operational amplifier, the reverse input end of the third operational amplifier is grounded through a seventh resistor, a PWM end is connected to pin No. 3 of a diode group, pin No. 1 of the diode group is connected to the output end, and pin No. 2 of the diode group is connected to the output end of the third operational amplifier.
[0006] Preferably, the voltage at the MCU end is 3.3V.
[0007] Preferably, the PWM terminal is connected to the inverting input terminal of the third operational amplifier through a first diode.
[0008] The beneficial effects of adopting the above technical solution are: the utility model can quickly limit the output current, solve the delay and possible failure of software protection, and avoid damage to the inverter module and even personal safety caused by short circuit in actual use. By comparing the current sampling with the threshold set by the hardware comparator, the response speed is fast, the working principle is simple and reliable, the protection point calculation is simple, accurate, and the adjustment is flexible. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Figure 1 It is a circuit diagram of a specific implementation of the utility model. DETAILED DESCRIPTION
[0010] Reference Figure 1 , the circuit input terminal INV_I of the utility model is respectively connected to the reverse input terminal of the first operational amplifier U1-A and the positive input terminal of the second operational amplifier U1-B, the positive input terminal of the first operational amplifier U1-A is connected to the MCU terminal through the first resistor R1, the positive input terminal of the first operational amplifier U1-A is grounded through the second resistor R2, the reverse input terminal of the second operational amplifier U1-B is connected to the MCU terminal through the third resistor R3, the reverse input terminal of the second operational amplifier U1-B is grounded through the fourth resistor R4, the output terminals of the first operational amplifier U1-A and the second operational amplifier U1-B are connected to the output terminal of the third operational amplifier U1-D, and the third The positive input terminal of the operational amplifier U1-D is connected to the MCU terminal through the fifth resistor R5, the positive input terminal of the third operational amplifier U1-D is connected to the output terminal of the third operational amplifier U1-D through the sixth resistor R6, the first capacitor C1 is connected between the positive input terminal of the third operational amplifier U1-D and the reverse input terminal of the third operational amplifier U1-D, the reverse input terminal of the third operational amplifier U1-D is grounded through the seventh resistor R7, the PWM terminal is connected to the No. 3 pin of the diode group D2, the No. 1 pin of the diode group D2 is connected to the output terminal INVPWM, and the No. 2 pin of the diode group D2 is connected to the output terminal of the third operational amplifier U1-D. The PWM terminal is connected to the reverse input terminal of the third operational amplifier U1-D through the first diode D1.
[0011] Taking the 230V-800W inverter as an example, the sine wave current sampling is based on 1.5V, the voltage at the MCU end is 3.3V, and by debugging the sampling resistor and amplification parameters, the rated power current sampling peak is ±0.5V, that is, the lower peak of INV_I is 1.5-0.5=1V and the upper peak is 1.5+0.5=2V. The above is the current sampling peak range of normal load.
[0012] Set U1A+ = 3.3V*R1 / (R1+R2) = 2.41V,
[0013] Set U1B- =3.3V*R3 / (R3+R4)=0.89V.
[0014] Within the rated load range, 1<INV_I<2, the OC gates of U1-A and U1-B are both high, and U1-D is high. At this time, the PWM end is output through the 3-1 pin of the diode group D2, and the inverter tube works normally.
[0015] When the output terminal is short-circuited or overloaded, INV_I increases with the output current. When INV_I>2.41 or INV_I<0.89, the OC gate of the output terminal of U1-A or U1-B is turned on, and the PWM terminal is pulled down through the 3-2 pin of the diode group D2, and the inverter tube drive stops immediately. U1D+ is pulled low, and the PWM terminal is connected to U1D- through the first diode D1, U1D->U1D+, and the output terminal of U1-D remains low until the MCU stops PWM. Then U1 is reset.
[0016] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.
Claims
1. A short-circuit protection circuit for output of a transfer and storage inverter module, characterized in that: The input terminal (INV_I) is connected to the inverting input terminal of the first op amp (U1-A) and the positive input terminal of the second op amp (U1-B), respectively. The positive input terminal of the first op amp (U1-A) is connected to the MCU terminal through the first resistor (R1). The positive input terminal of the first op amp (U1-A) is grounded through the second resistor (R2). The inverting input terminal of the second op amp (U1-B) is connected to the MCU terminal through the third resistor (R3). The inverting input terminal of the second op amp (U1-B) is grounded through the fourth resistor (R4). The output terminals of the first op amp (U1-A) and the second op amp (U1-B) are connected to the output terminal of the third op amp (U1-D). The positive input terminal of the third operational amplifier (U1-D) is connected to the MCU terminal through a fifth resistor (R5), the positive input terminal of the third operational amplifier (U1-D) is connected to the output terminal of the third operational amplifier (U1-D) through a sixth resistor (R6), a first capacitor (C1) is connected between the positive input terminal of the third operational amplifier (U1-D) and the reverse input terminal of the third operational amplifier (U1-D), the reverse input terminal of the third operational amplifier (U1-D) is grounded through a seventh resistor (R7), the PWM terminal is connected to pin No. 3 of the diode group (D2), pin No. 1 of the diode group (D2) is connected to the output terminal (INVPWM), and pin No. 2 of the diode group (D2) is connected to the output terminal of the third operational amplifier (U1-D).
2. The output short-circuit protection circuit of the power transfer and storage inverter module according to claim 1 is characterized in that: The voltage at the MCU end is 3.3V.
3. The output short-circuit protection circuit of the power transfer and storage inverter module according to claim 1 is characterized in that: The PWM terminal is connected to the inverting input terminal of the third operational amplifier (U1-D) through a first diode (D1).