CN-121055777-B - Photovoltaic energy storage integrated three-port hydrogen production power supply and control method thereof

CN121055777BCN 121055777 BCN121055777 BCN 121055777BCN-121055777-B

Abstract

The invention belongs to the field of direct current converters, and provides a photovoltaic energy storage integrated three-port hydrogen production power supply and a control method thereof, wherein the main scheme is that gate driving signals of a first switching tube and a second switching tube are obtained, and the gate driving signals of the first switching tube and the gate driving signals of the second switching tube are complementary; the method comprises the steps of obtaining gate driving signals of a third switching tube and a fourth switching tube, obtaining gate driving signals of a fifth switching tube and a sixth switching tube, obtaining gate driving signals of the fifth switching tube and the sixth switching tube, adjusting the duty ratio of the first switching tube through a control circuit to control the input power of a photovoltaic cell, and adjusting the phase-shifting angle of the fifth switching tube lagging behind the first switching tube through the control circuit to control the output voltage of the converter. The invention eliminates the circulation in the whole switching period, widens the voltage gain range of the load port, and remarkably inhibits the output current ripple.

Inventors

HUANG JINFEI
MENG XIN
TIAN QINGXIN
HE MINGZHI
ZHANG YICHI
GE WEI

Assignees

四川大学

Dates

Publication Date: 20260508
Application Date: 20250818

Claims (7)

1. A photovoltaic energy storage integrated three-port hydrogen generation power supply, comprising: The device comprises a primary circuit, a first high-frequency isolation transformer, a second high-frequency isolation transformer, a control circuit, a rectifying circuit, an auxiliary circuit, an output filter capacitor and a load; The primary circuit comprises a photovoltaic cell, a first input capacitor, a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, an energy storage battery and a second input capacitor, the rectifying circuit comprises a first diode, a second diode, a fifth switching tube, a sixth switching tube, a first filter capacitor and a second filter capacitor, the auxiliary circuit comprises a third high-frequency isolation transformer, an auxiliary inductor and an auxiliary capacitor, the first high-frequency isolation transformer comprises a first primary winding and a first secondary winding, the second high-frequency isolation transformer comprises a second primary winding and a second secondary winding, and the third high-frequency isolation transformer comprises a third primary winding and a third secondary winding; The control circuit is used for controlling the input power of the photovoltaic cell by adjusting the duty ratio of the first switching tube and controlling the output voltage of the converter by adjusting the phase shift angle of the fifth switching tube lagging behind the first switching tube; The positive end of the photovoltaic cell is respectively connected with one end of the first input capacitor, the drain electrode of the first switching tube and the drain electrode of the third switching tube, the source electrode of the first switching tube is respectively connected with the drain electrode of the second switching tube and the homonymous end of the first primary winding, the source electrode of the third switching tube is respectively connected with the drain electrode of the fourth switching tube and the non-homonymous end of the second primary winding, the non-homonymous end of the first primary winding is respectively connected with the homonymous end of the second primary winding, the positive end of the energy storage battery and one end of the second input capacitor, and the negative end of the photovoltaic cell is respectively connected with the other end of the first input capacitor, the negative end of the energy storage battery, the other end of the second input capacitor, the source electrode of the second switching tube and the source electrode of the fourth switching tube; The same-name end of the first secondary winding is respectively connected with the anode of the first diode and the drain electrode of the sixth switching tube, the non-same-name end of the first secondary winding is respectively connected with the same-name end of the second secondary winding, one end of the first filter capacitor and one end of the second filter capacitor, the non-same-name end of the second secondary winding is respectively connected with the drain electrode of the fifth switching tube and the anode of the second diode, the cathode of the first diode is respectively connected with the other end of the first filter capacitor, the cathode of the second diode, the same-name end of the third primary winding and the same-name end of the third secondary winding, the non-same-name end of the third secondary winding is connected with one end of the auxiliary inductor, the other end of the auxiliary inductor is connected with one end of the auxiliary capacitor, the non-same-name end of the third primary winding is respectively connected with one end of the output filter capacitor and the positive end of the load, and the source electrode of the sixth switching tube is respectively connected with the other end of the second filter capacitor, the source of the fifth switching tube, the other end of the auxiliary capacitor, the other end of the output filter capacitor and the negative end of the load.
2. The integrated three-port hydrogen generation power supply of claim 1, wherein when the control circuit controls the input power of the photovoltaic cell by adjusting the duty cycle of the first switching tube, the control circuit comprises: The MPPT algorithm unit, the first subtracter, the first error amplifier, the first comparator, the second comparator, the first NOT gate and the second NOT gate; One input end of the MPPT algorithm unit is input voltage V in of the direct current converter, the other input end of the MPPT algorithm unit is input current I in of the direct current converter, the output end of the MPPT algorithm unit is connected to the negative input end of the first subtracter, the positive input end of the first subtracter is input voltage V in of the direct current converter, the output end of the first subtracter is connected to the input end of the first error amplifier, and the output ends of the first error amplifier are respectively connected to the positive input ends of the first comparator and the second comparator; The negative input end of the first comparator is used for inputting a sawtooth wave v t , the output end of the first comparator generates a driving signal and is used for being connected to the grid electrode of the first switching tube, and the output end of the first comparator passes through the first NOT gate and is used for being connected to the grid electrode of the second switching tube; The negative input end of the second comparator is used for inputting the sawtooth wave v t after 180 degrees of phase shift, the output end of the second comparator generates a driving signal and is used for being connected to the grid electrode of the third switching tube, and the output end of the second comparator passes through the second NOT gate and is used for being connected with the grid electrode of the fourth switching tube.
3. The integrated three-port hydrogen generation power supply of claim 2, wherein the control circuit controls the input power of the photovoltaic cell by adjusting the duty cycle of the first switching tube, comprising the steps of: Calculating an input voltage V in of the direct current converter and an input current I in of the direct current converter through an MPPT algorithm unit to obtain an input reference voltage V in_ref , and obtaining a first error signal V in -V in_ref through a first subtracter by the input reference voltage V in_ref and the input voltage V in of the direct current converter; The first error signal is subjected to a first error amplifier to obtain a first error amplified signal v ea1 , and the first error amplified signal is compared with a set sawtooth wave signal v saw (t) through a first comparator to obtain a grid driving signal of a first switching tube; the grid driving signal of the first switching tube is obtained after passing through a first NOT gate, and the grid driving signal of the second switching tube is obtained after the grid driving signal of the first switching tube is opposite; Comparing the first error amplified signal with a sawtooth wave signal v saw (t) subjected to 180 DEG phase shift through a second comparator to obtain a gate driving signal of a third switching tube; And (3) the grid driving signal of the third switching tube is subjected to second NOT gate taking and is opposite to the second NOT gate taking, so that the grid driving signal of the fourth switching tube is obtained.
4. The integrated three-port hydrogen generation power supply of claim 1, wherein when the control circuit controls the output voltage of the converter by adjusting the phase angle of the fifth switching tube that lags the first switching tube, the control circuit comprises: a second subtractor, a second error amplifier, a third comparator, and a third NOT gate; The positive input end of the second subtracter is bus reference voltage V o_ref , the negative input end of the second subtracter is bus sampling voltage V o , the output end of the second subtracter is connected to the input end of the second error amplifier, and the output end of the second error amplifier generates a phase shift angle ; The positive input end of the third comparator is used for accessing a 0.5 reference level, the negative input end of the third comparator is used for inputting the saw-tooth wave v t after phase shifting, the output end of the third comparator generates a driving signal and is used for being connected to the grid electrode of the fifth switching tube, and meanwhile, the output end of the third comparator is used for being connected to the grid electrode of the sixth switching tube after passing through the third NOT gate.
5. The integrated three-port hydrogen generation power supply of claim 4 wherein said control circuit controls the output voltage of the converter by adjusting the phase shift angle of the fifth switching tube to lag the first switching tube, comprising the steps of: Obtaining a second error signal V o_ref -V o by a second subtracter through the sampled converter output voltage V o and the set bus reference voltage V o_ref ; obtaining a phase shift angle by passing the second error signal through a second error amplifier ; Comparing the 0.5 reference level with the saw-tooth wave signal v saw (t) after phase shifting through a third comparator to obtain a grid driving signal of a fifth switching tube; And (3) the grid driving signal of the fifth switching tube is subjected to third NOT gate taking and reversing to obtain the grid driving signal of the sixth switching tube.
6. A photovoltaic energy storage integrated three port hydrogen generation power supply as claimed in any one of claims 1 to 5 wherein in said primary side circuit: The first switching tube and the third switching tube have the same duty ratio, the third switching tube lags behind the first switching tube by 180 DEG for conduction, the first switching tube and the second switching tube are complementarily conducted, and the third switching tube and the fourth switching tube are complementarily conducted; In the rectifying circuit: the fifth switching tube and the sixth switching tube are complementarily conducted at a duty ratio of 0.5, and the driving signal of the fifth switching tube lags behind the first switching tube by a phase shift angle, and the lag phase shift angle is used for controlling the output voltage of the converter.
7. A control method for a photovoltaic energy storage integrated three-port hydrogen production power supply, which is applied to the photovoltaic energy storage integrated three-port hydrogen production power supply as claimed in any one of claims 1 to 6, and is characterized by comprising the following steps: Acquiring gate driving signals of a first switching tube and a second switching tube, wherein the gate driving signals of the first switching tube are complementary with the gate driving signals of the second switching tube; Acquiring gate driving signals of a third switching tube and a fourth switching tube, wherein the gate driving signals of the third switching tube are complementary with the gate driving signals of the fourth switching tube; Acquiring gate driving signals of a fifth switching tube and a sixth switching tube, wherein the gate driving signals of the fifth switching tube are complementary with the gate driving signals of the sixth switching tube; the duty ratio of the first switching tube is adjusted through the control circuit to control the input power of the photovoltaic cell; the output voltage of the converter is controlled by adjusting the phase shift angle of the fifth switching tube lagging behind the first switching tube through the control circuit.

Description

Photovoltaic energy storage integrated three-port hydrogen production power supply and control method thereof Technical Field The invention relates to the technical field of direct current converters, in particular to a photovoltaic energy storage integrated three-port hydrogen production power supply and a control method thereof. Background In the context of global energy transformation acceleration, renewable energy development and efficient electric energy conversion technologies are becoming research hotspots. The hydrogen production power supply is used as a key interface device for efficiently converting renewable energy into hydrogen energy, and the performance of the hydrogen production power supply directly influences the overall efficiency, reliability and economy of the renewable energy hydrogen production system. The three-port converter can realize flexible matching of multi-energy input and multi-load output, and has important application value in the scenes of a photovoltaic energy storage system, an electrolytic hydrogen production device and the like. In the existing hydrogen production power supply technology, a plurality of problems to be optimized generally exist in a structure based on a traditional half bridge or a full bridge. First, the circulating current phenomenon caused by leakage inductance of the transformer and parasitic parameters of the circuit during the high frequency switching process may cause significant additional power loss, severely reducing the energy transfer efficiency from the renewable energy source to the electrolyzer. And secondly, the voltage gain range of the load port is limited, the wide-range fluctuation of the output voltage of the photovoltaic cell is difficult to adapt, and meanwhile, the strict requirement of the electrolytic hydrogen production device on the input voltage cannot be met. In addition, the primary side switching tube is operated in a hard switching state, and the switching loss of the primary side switching tube is increased sharply along with the increase of the operating frequency, so that the development of the hydrogen production power supply in the high-frequency, small-sized and light-weight directions is restricted, and the further improvement of the efficiency is also restricted. In view of the above technical bottlenecks, various improvement strategies have been proposed in the prior art. For example, the introduction of multiple phase shifting controls to suppress the loop current and optimize the power transfer path, however, this significantly increases the complexity of the control system and limits the implementation range of the soft switch, and the adoption of a cascaded structure or hybrid multi-level topology can effectively extend the voltage gain range of the load port, but tends to result in a reduction in the overall efficiency of the converter. Therefore, the high-performance hydrogen production power supply which can eliminate the circulation current in the full switching period, expand the voltage gain range of the load port, realize soft switching and restrain the output current ripple is developed, and has important engineering application value. Disclosure of Invention The invention aims to provide a photovoltaic energy storage integrated three-port hydrogen production power supply and a control method thereof, which not only eliminate circulation in the whole switching period and effectively improve the power transmission capacity of a system, but also widen the voltage gain range of a load port, simultaneously reduce the volume of a required output filter, and in addition, obviously inhibit output current ripple by combining an adopted auxiliary circuit. The invention solves the technical problems and adopts the following technical scheme: in one aspect, the invention provides a photovoltaic energy storage integrated three-port hydrogen production power supply, comprising: The device comprises a primary circuit, a first high-frequency isolation transformer, a second high-frequency isolation transformer, a control circuit, a rectifying circuit, an auxiliary circuit, an output filter capacitor and a load; The primary circuit comprises a photovoltaic cell, a first input capacitor, a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, an energy storage battery and a second input capacitor, the rectifying circuit comprises a first diode, a second diode, a fifth switching tube, a sixth switching tube, a first filter capacitor and a second filter capacitor, the auxiliary circuit comprises a third high-frequency isolation transformer, an auxiliary inductor and an auxiliary capacitor, the first high-frequency isolation transformer comprises a first primary winding and a first secondary winding, the second high-frequency isolation transformer comprises a second primary winding and a second secondary winding, and the third high-frequency isolation transformer comprises a thi