CN209217949U - A kind of concatenated high-gain boost converter of output capacitance - Google Patents

Abstract

The utility model discloses a kind of concatenated high-gain boost converter of output capacitance, including input power V_in, input filter inductance L, power switch tube S, boost capacitor C₁, the first output capacitance C₂, the second output capacitance C₃, first diode D₁, the second diode D₂With third diode D₃, the grid connection control signal voltage V of power switch tube S_gs, drain and be connected to node 1, source electrode is connected to input power V_inCathode, concatenated first output capacitance C₂, the second output capacitance C₃Both ends be boost converter output end, load R be connected in parallel on output end.The utility model circuit structure is simple, and conversion gain is high.

Description

A High Gain Boost Converter with Output Capacitors in Series

technical field

The utility model relates to a high-gain boost converter with output capacitors connected in series, which belongs to the field of power electronic converters.

Background technique

The DC micro-grid system that meets local electric energy supply has received more and more attention. Among them, photovoltaic power generation, wind power generation and other power generation systems in the field of renewable energy, as DC power sources, have become one of the research hotspots. These power systems have the common disadvantage of low output voltage, and it is difficult to output power-frequency AC power after inversion, which requires a step-up DC converter to increase the voltage. The traditional boost converter can increase the voltage, the circuit structure is simple, and the reliability is high. However, due to the influence of parameters such as parasitic resistance, it can only achieve a voltage increase of about five times in industrial applications, which cannot meet the needs of modern industry. In order to achieve a higher gain, many boost technologies have been proposed: coupled inductor boost technology, switched capacitor boost technology, switched inductor boost technology or an effective combination of multiple boost technologies, etc. These high-gain converter circuit structures It is more complicated, the voltage stress of the switching device is uneven, and the reliability is reduced.

Contents of the invention

The technical problem to be solved by the utility model is to provide a high-gain boost converter with output capacitors connected in series, which has a simple circuit structure and high conversion gain.

In order to solve the technical problem, the technical solution adopted by the utility model is: a high-gain boost converter with an output capacitor connected in series, including an input power supply V _in , an input filter inductor L, a power switch tube S, a boost capacitor C ₁ , The first output capacitor C ₂ , the second output capacitor C ₃ , the first diode D ₁ , the second diode D ₂ and the third diode D ₃ , the input filter inductor L, the third diode D ₃ 1. The first output capacitor _C2 is connected in series between the positive pole and the negative pole of the input power supply _Vin , the positive pole of the third diode _D3 is connected to the input filter inductor L, the negative pole is connected to one end of the first output capacitor _C2 , and the third diode D3 The node between the anode of tube _D3 and the input filter inductor L is called node 1, and the _second diode D2 and boost capacitor are connected in series between the other end of the first output capacitor C2 and node ₁ C ₁ , the anode of the second diode D ₂ is connected to the other end of the second output capacitor C ₃ , the cathode is connected to one end of the boost capacitor C ₁ , the gate of the power switch tube S is connected to the control signal voltage V _gs , and the drain is connected to to node 1, the source is connected to the negative pole of the input power supply _Vin , the anode of the _first diode D1 is connected to the node between the _second diode D2 and the boost capacitor _C1 , and the negative pole is connected to the input The node between the negative pole of the power supply V _in and the first input capacitor C ₂ ; the two ends of the first output capacitor C ₂ and the second output capacitor C ₃ in series are the output terminals of the boost converter, and the load R is connected in parallel at the output terminal .

Further, the power switch tube is a mos tube.

Further, the boost converter has three switching modes. When it is in switching mode 1, the power switch tube S is turned on, the third diode and the first diode are turned off, and the input power supplies the input filter inductance to charge; In switching mode 2, the power switch tube, the second diode and the third diode are cut off, and the input power supply and input filter inductor jointly charge the boost capacitor through the first diode; in switching mode 3, the power The switch tube and the second diode are cut off, the input power supply and the input filter inductor jointly charge the boost capacitor through the first diode; in the three switching modes, the first output capacitor and the second output capacitor are connected in series to provide the load with electrical energy.

Further, the gain M of the boost converter is: Among them, D is the conduction duty cycle of the power switch tube.

Beneficial effects of the utility model: the utility model has simple circuit structure, high conversion gain, small device voltage stress and high conversion efficiency.

Description of drawings

Figure 1 is a circuit schematic diagram of a high-gain boost converter with output capacitors connected in series;

Figure 2 is a modal diagram of a high-gain boost converter with output capacitors connected in series;

Figure 3a is an equivalent circuit diagram of switching mode 1 of a high-gain Boost converter with output capacitors connected in series;

Figure 3b is an equivalent circuit diagram of switching mode 2 of a high-gain Boost converter with output capacitors connected in series;

Fig. 3c is an equivalent circuit diagram of switching mode 3 of a high-gain Boost converter with output capacitors connected in series;

Fig. 4 is when input voltage _Vin =20V, and voltage gain M is 4, and output power is the Pspice simulation waveform of 80W;

Explanation of symbols in the figure: V _in is the input power supply, S is the power switch tube, the input filter inductor L, the first diode D ₁ , the second diode D ₂ , the third diode D ₃ , and the boost capacitor C ₁ , the first output capacitor C ₂ , the second output capacitor C ₃ , and R is the load.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the utility model is described further.

Example 1

This embodiment discloses a high-gain boost converter with an output capacitor connected in series, as shown in FIG. 1 , including an input power supply V _in , an input filter inductor L, a power switch tube S, a boost capacitor C ₁ , and a first output capacitor C ₂ , the second output capacitor C ₃ , the first diode D ₁ , the second diode D ₂ and the third diode D ₃ , the input filter inductor L, the third diode D ₃ , the first output capacitor C ₂ is connected in series between the anode and cathode of the input power supply V _in , the anode of the third diode _D3 is connected to the input filter inductor L, the cathode is connected to one end of the first output capacitor _C2 , and the anode of the third diode _D3 is connected to The node between the input filter inductor L is called node 1, the second diode D ₂ and the boost capacitor C 1 are connected in series between the other end of the first output capacitor C ₂ and the node ₁ , the second two The positive pole of the pole tube D2 is connected to the other end _of the _second output capacitor C3, the negative pole is connected to _one end of the boost capacitor C1, the gate of the power switch tube S is connected to the control signal voltage V _gs , the drain is connected to node 1, and the source The pole is connected to the negative pole of the input power supply V _in , the anode of the _first diode D1 is connected to the node between the _second diode D2 and the boost capacitor _C1 , and the negative pole is connected to the negative pole of the input power supply _Vin and The node between the first input capacitor C ₂ ; the two ends of the first output capacitor C ₂ and the second output capacitor C ₃ connected in series are the output end of the boost converter, and the load R is connected in parallel to the output end.

In this embodiment, the power switch tube is a mos tube, and an IGBT tube may also be used.

The working principle and working process of the high-gain boost converter with output capacitors connected in series in this embodiment are as follows:

The high-gain Boost converter with the output capacitor connected in series controls the signal voltage V _gs , the input filter inductor current i _L , and the first diode current second diode current third diode current The waveform of the power switch tube current i _s is shown in Figure 2, and its working process is divided into three switching modes, namely switching mode 1 to switching mode 3, and the specific description is as follows:

Switching mode 1, corresponding to [t ₀ , t ₁ ] in Figure 2: the equivalent circuit is shown in Figure 3(a), the power switch S is turned on at time t ₀ , the third diode and the first diode due. The input power supply charges the input filter inductor, the input filter inductor current i _L rises approximately linearly, the boost capacitor charges the second output capacitor, and the second diode current Decreasing in exponential form, the first output capacitor and the second output capacitor are connected in series to jointly provide electric energy for the load. At time t ₁ , the power switch tube S is turned off.

Switching mode 2, corresponding to [t ₁ ,t ₂ ] in Figure 2: the equivalent circuit is shown in Figure 3(b), the power switch tube, the second diode and the third diode are cut off, the input power and The input filter inductor charges the boost capacitor together through the first diode, and the current of the first diode Almost unchanged, the first output capacitor and the second output capacitor are connected in series to provide electric energy for the load.

Switching mode 3, corresponding to [t ₂ , t ₃ ] in Figure 2: the equivalent circuit is shown in Figure 3(c), the power switch tube and the second diode are cut off, the input power supply and the input filter inductor pass through the first The diodes together charge the boost capacitor, the first diode current Approximate linear decline, the input power supply and the input filter inductor charge the first output filter capacitor through the third diode, and the third diode current It rises approximately linearly and then remains almost constant. The first output capacitor and the second output capacitor are connected in series to provide electric energy for the load. When the power switch S is turned on, a new switching cycle starts.

From the above analysis, the gain expression can be obtained as:

Among them, D is the conduction duty cycle of the power switch tube.

Due to the influence of parasitic parameters and other factors, the traditional boost converter can only increase the input voltage by five times, which is difficult to meet high-gain applications (generally ten or higher). Scholars from various countries have proposed many high-gain converters: high-gain converters based on coupled inductor technology, high-gain converters based on switched capacitor technology, or high-gain converters composed of a combination of the two, but they all have complex circuit structures. The power density is low, and the voltage stress of some devices is relatively large. However, in this converter, the circuit structure is simple, the operation mode is clear, and the device voltage stress is low, which meets the high-gain application occasions.

The beneficial effect of adopting the structure of the present invention is illustrated below by concrete Pspice simulation examples:

As shown in Figure 4, the input voltage _Vin = 20V, the voltage gain M is 4, and the output power is 80W. The current waveform and voltage waveform of each device are shown in the figure, and the voltage stress is much smaller than the output voltage, which effectively verifies the aforementioned theoretical accuracy.

The above description is only the basic principles and preferred embodiments of the present utility model, and the improvements and replacements made by those skilled in the art according to the present utility model belong to the protection scope of the present utility model.

Claims (4)

1. A high-gain boost converter with output capacitors connected in series, characterized in that: it includes an input power supply V _in , an input filter inductor L, a power switch tube S, a boost capacitor C ₁ , a first output capacitor C ₂ , and a second output Capacitor C ₃ , first diode D ₁ , second diode D ₂ and third diode D ₃ , input filter inductor L, third diode D ₃ , and first output capacitor C ₂ are connected in series at the input Between the anode and cathode of the power supply V _in , the anode of the third diode _D3 is connected to the input filter inductor L, the cathode is connected to one end of the first output capacitor _C2 , the anode of the third diode _D3 is connected to the input filter inductor L The node between is called node 1, the second diode D ₂ and boost capacitor C 1 are connected in series between the other end of the first output capacitor C ₂ and node ₁ , the second diode D ₂ The positive pole of the power switch S is connected to the other end of the second output capacitor C ₃ , the negative pole is connected to one end of the boost capacitor C ₁ , the gate of the power switch S is connected to the control signal voltage V _gs , the drain is connected to node 1, and the source is connected to the input The negative pole of the power supply V _in , the positive pole of the _first diode D1 is connected to the node between the _second diode D2 and the boost capacitor _C1 , and the negative pole is connected to the negative pole of the input power supply _Vin and the first input capacitor The node between C ₂ ; both ends of the first output capacitor C ₂ and the second output capacitor C ₃ connected in series are the output terminals of the boost converter, and the load R is connected in parallel to the output terminals. 2. The high-gain boost converter with output capacitors connected in series according to claim 1, characterized in that: the power switch tube is a mos tube. 3. the high-gain boost converter of output capacitance series connection according to claim 1, it is characterized in that: described boost converter has 3 kinds of switching modes, when being in switching mode 1, power switch tube S is opened, and the third The diode and the first diode are cut off, and the input power supply charges the input filter inductor; in switching mode 2, the power switch tube, the second diode and the third diode are cut off, and the input power supply and the input filter inductor pass through The first diode jointly charges the boost capacitor; when in switching mode 3, the power switch tube and the second diode are cut off, and the input power supply and input filter inductor jointly charge the boost capacitor through the first diode; 3 In this switching mode, the first output capacitor and the second output capacitor are connected in series to provide electric energy for the load. 4. the high-gain boost converter of output capacitance series connection according to claim 3, is characterized in that: the gain M of described boost converter is: Among them, D is the conduction duty cycle of the power switch tube.