CN211557149U

CN211557149U - Boost circuit of direct-hanging high-voltage power supply

Info

Publication number: CN211557149U
Application number: CN201922305976.0U
Authority: CN
Inventors: 陈建明; 王波; 卢钢; 章旌红
Original assignee: ZHEJIANG HRV ELECTRIC CO Ltd
Current assignee: ZHEJIANG HRV ELECTRIC CO Ltd
Priority date: 2019-12-20
Filing date: 2019-12-20
Publication date: 2020-09-22
Anticipated expiration: 2029-12-20

Abstract

The utility model discloses a booster circuit of a direct-hanging high-voltage power supply, which comprises an inductor L1, a switch S1, a diode D1 and a diode D2, one end of the inductor L1 is connected with the anode of the capacitor C1, the switch K1 and the diode D3, the other end of the switch K1 is connected with the low-voltage power supply, the other end of the inductor L1 is connected with the anode of the switch S1 and the diode D1, the cathode of the diode D1 is connected with the anode of the capacitor Cfly, the resistor RS3 and the diode D2, in the application scene circuit of the output direct-hanging high-voltage power supply, by using the three-level flying capacitor circuit of the utility model and the unique soft start circuit, the voltage level of all switches of the system can be reduced by half, because the low-voltage semiconductor switch has good characteristics and high selectivity, the high frequency of the whole circuit can be realized, the volume of the inductor is reduced, the volume of the whole mechanism is further reduced, and the cost of the whole system is reduced.

Description

Boost circuit of direct-hanging high-voltage power supply

Technical Field

The utility model relates to a power technical field specifically is a direct-hanging high voltage power supply's boost circuit.

Background

In view of the current increasingly serious environmental pollution, the nation is beginning to develop new energy vehicles, especially hydrogen fuel cell vehicles, and the fuel cell vehicles receive hydrogen and oxygen at the front end, and discharge water except for electric energy after electrochemical reaction without any pollution, so the vehicles are regarded as ideal clean energy.

Although fuel cells have many advantages, as vehicle-mounted energy sources, because output voltage and current characteristics are soft, rated operating voltage is low, and the fuel cells are unstable under disturbance, a DC/DC converter needs to be added between the fuel cells and a motor controller to convert and stabilize voltage, as shown in fig. 1, so that the fuel cells can stably cooperate with an inverter. Meanwhile, a high-voltage vehicle-mounted power supply is generally connected in parallel between the DCDC and the motor controller, and when the fuel cell cannot normally provide load energy or fails, the high-voltage battery can be switched to supply power to the inverter, so that the vehicle can continue to work stably.

Fig. 2 is a conventional DCDC power supply scheme, which employs a conventional two-level boost circuit, and because the voltage ratio of the fuel cell is low and the voltage ratio of the high-voltage battery is high, a 1200V switching tube is generally required (in view of the current vehicle yards, efforts are being made to improve efficiency, and improve the voltage level of the motor driver, and the 1200V device is not excluded in the later stage). If the switching tube of the SIC is adopted, the frequency can be increased, but the cost is high, and the method is not economical.

Fig. 3 is a commonly used three-level flying capacitor boost circuit, which can realize stable operation by adding voltage control of a flying capacitor. Compared with the traditional two-level booster circuit, the switching tube has low voltage stress, can select a switching tube with half of the battery voltage (such as a MOSFET (metal oxide semiconductor field effect transistor) with 600V and 650V or a high-frequency IGBT (insulated gate bipolar transistor)) which is commonly used in the market at present, has good switching characteristic and low loss, and can be operated at high frequency; the inductor has the frequency doubling characteristic, and is small in size and high in efficiency. Therefore, the DCDC size can be made small, the mechanism cost is saved, and the whole system cost is lower.

In the circuit of fig. 3, when the switch KS2 is closed, the high-voltage battery charges the C2 and C3, and when the voltage of the BUS reaches the soft start voltage amplitude, the switch KS2 is opened, the switch K2 is closed, the voltage of the BUS is equal to the voltage of the high-voltage battery, and at this time, because the input low-voltage power supply side does not work, the voltage of the input side is 0, and the initial voltage of the flying capacitor is 0, the voltage of the BUS is completely applied to the diode D2, so that the diode is damaged by overvoltage, or the D2 only needs to select a high-voltage switch tube.

Based on the above, the boost circuit is to be improved.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a direct-hanging high voltage power supply's boost circuit to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme:

a boost circuit of a direct-hanging high-voltage power supply comprises an inductor L1, a switch S1, a diode D1 and a diode D2, wherein one end of the inductor L1 is connected with anodes of a capacitor C1, a switch K1 and a diode D1, the other end of the switch K1 is connected with a low-voltage power supply, the other end of the inductor L1 is connected with anodes of the switch S1 and the diode D1, a cathode of the diode D1 is connected with anodes of the capacitor Cfly, the resistor RS1 and an anode of the diode D1, the other end of the switch S1 is connected with the other ends of the switch S1 and the capacitor Cfly, the other end of the capacitor C1 is connected with the other end of the switch S1, the other end of the low-voltage power supply, the capacitor C1 and the high-voltage power supply, a cathode of the diode D1 is connected with the capacitor C1, the other end of the switch K1 is connected with the other end of the diode D1 and the cathode of the capacitor C1, the anode of the diode D4 is connected to the switch S1 and the switch S2.

As a further aspect of the present invention: the cathode of the diode D1 is also connected with a resistor RS3, the other end of the resistor RS3 is connected with a switch KS3, and the other end of the switch KS3 is connected with a high-voltage power supply and a switch K2.

As a further aspect of the present invention: the cathode of the diode D1 is also connected with a switch KS3, and the other end of the switch KS3 is connected with the cathode of the diode D2.

As a further aspect of the present invention: one end of the switch K1 is connected with a switch KS1, the other end of the switch K1 is connected with a resistor RS1, and the other end of the switch KS1 is connected with the other end of the resistor RS 1.

As a further aspect of the present invention: the diode D3 is a silicon diode.

As a further aspect of the present invention: the switch KS3 is a normally closed switch.

Compared with the prior art, the beneficial effects of the utility model are that: the utility model discloses in the high voltage power supply application scene circuit is directly hung in output, through using neotype three level flying capacitor circuit to its unique soft circuit that opens of collocation can reduce all switching voltage levels of system half, because low pressure semiconductor switch characteristic is good and the optional degree is high, consequently can realize the high frequency of whole circuit, reduces the inductance volume, and then reduces the volume of whole mechanism, reduces entire system's cost.

Drawings

Fig. 1 is a diagram of a conventional booster circuit.

Fig. 2 is a circuit diagram of a conventional DC-DC power supply.

Fig. 3 is a diagram of a conventional three-level flying capacitor boost circuit.

Fig. 4 is a circuit diagram of a first embodiment of the present invention.

Fig. 5 is a circuit diagram of a second embodiment of the present invention.

Fig. 6 is a high frequency design circuit diagram according to a first embodiment of the present invention.

Fig. 7 is a high frequency design circuit diagram according to a second embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 4, embodiment 1: in the embodiment of the utility model, a booster circuit of a direct-hanging high-voltage power supply,

a boost circuit of a direct-hanging high-voltage power supply comprises an inductor L1, a switch S1, a diode D1 and a diode D2, wherein one end of the inductor L1 is connected with anodes of a capacitor C1, a switch K1 and a diode D1, the other end of the switch K1 is connected with a low-voltage power supply, the other end of the inductor L1 is connected with anodes of the switch S1 and the diode D1, a cathode of the diode D1 is connected with anodes of the capacitor Cfly, the resistor RS1 and an anode of the diode D1, the other end of the switch S1 is connected with the other ends of the switch S1 and the capacitor Cfly, the other end of the capacitor C1 is connected with the other end of the switch S1, the other end of the low-voltage power supply, the capacitor C1 and the high-voltage power supply, a cathode of the diode D1 is connected with the capacitor C1, the other end of the switch K1 is connected with the other end of the diode D1 and the cathode of the capacitor C1, the anode of the diode D4 is connected to the switch S1 and the switch S2. The circuit is added with KS3, RS3 and D4, when the control system is powered on, the host computer sends out a starting instruction, the power supply enters a starting state, KS2 and KS3 are closed at first, and a high-voltage power supply forms a charging loop with KS2, RS2, C2 and C3; meanwhile, a charging loop is formed by the high-voltage power supply through KS3, RS3, Cfly and C3, the capacitance value of the Cfly is relatively small generally, after the Cfly voltage is larger than the C2 voltage, a charging loop is formed by the high-voltage battery side through KS3, RS3, D2, C2 and C3 until the system detects that C2, C3 and Cfly voltages meet the starting voltage, K2 is closed, KS2 and KS3 are opened simultaneously, and the DCDC power supply and the high-voltage power supply are hung together. And then KS1 is closed, the low-voltage power supply side charges C1 through KS1 and RS1, and also when the C1 voltage is detected to meet the starting condition, K1 is closed, KS1 is opened at the same time, the low-voltage side is hung with the DCDC, and then the DCDC performs a normal operation mode, which is the same as the traditional three-level flying capacitor operation mode.

Example 2: based on embodiment 1, as shown in fig. 5, KS3 and D4 are added, where KS3 is a normally closed switch, and when the control system is powered on, the host computer issues a power-on command, and the power supply enters a start state, and at first, KS2 is closed, and the high-voltage power supply forms a charging loop through KS2, RS2, C2, and C3; meanwhile, the high-voltage power supply forms a charging loop through KS2, RS2, KS3, Cfly and C3, K2 is closed after the system detects that C2, C3 and Cfly voltages meet starting voltages, KS2 and KS3 are opened at the same time, and at the moment, because C2 and the Cfly voltages are the same, the KS3 is disconnected without loss, and the DCDC power supply and the high-voltage power supply are hung together. And then KS1 is closed, the low-voltage power supply side charges C1 through KS1 and RS1, and also when the C1 voltage is detected to meet the starting condition, K1 is closed, KS1 is opened at the same time, the low-voltage side is hung with the DCDC, and then the DCDC performs a normal operation mode, which is the same as the traditional three-level flying capacitor operation mode.

Meanwhile, the input capacitor soft start circuit can be omitted in consideration of the fact that the capacitor soft start circuit is limited in current capacity when the capacitor soft start circuit is applied to fuel cells and similar power supply products, at the moment, due to the high-frequency sampling design, the inductor ripple current is small, the capacity of the C1 is very small compared with a traditional two-level circuit, when the K1 is closed, the flowing impact current is short compared with the traditional circuit, and the system stability is good.

Compared with a traditional three-level flying capacitor, the high-voltage starting circuit is added, the diode is effectively guaranteed not to be overvoltage, and extra loss is not increased in the whole circuit.

A high-voltage silicon diode D3 is added, when the input voltage can meet the load voltage requirement, the input energy is directly released to the load through K1, D3 and K3, and the loss of the load release capacity is smaller than that of the energy released to the load through K1, L1, D1, D2 and K2, the efficiency is high, and the high-voltage silicon diode D3 can be omitted if no application scene exists.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. A boost circuit of a direct-hanging high-voltage power supply comprises an inductor L1, a switch S1, a diode D1 and a diode D2, wherein one end of the inductor L1 is connected with anodes of a capacitor C1, a switch K1 and a diode D1, the other end of the switch K1 is connected with a low-voltage power supply, the other end of the inductor L1 is connected with anodes of the switch S1 and the diode D1, a cathode of the diode D1 is connected with anodes of the capacitor Cfly, the resistor RS1 and the diode D1, the other end of the switch S1 is connected with the other ends of the switch S1 and the capacitor Cfly, the other end of the capacitor C1 is connected with the other end of the low-voltage power supply, the capacitor C1 and the high-voltage power supply, a cathode of the diode D1 is connected with the capacitor C1, the resistor RS1 and the switch K1, the other end of the switch K1 is connected with the other end of the switch KS1 and the cathode of the diode D1, the anode of the diode D4 is connected to the switch S1 and the switch S2.

2. The voltage boost circuit of a direct-hanging high-voltage power supply as claimed in claim 1, characterized in that the cathode of said diode D1 is further connected with a resistor RS3, the other end of the resistor RS3 is connected with a switch KS3, and the other end of the switch KS3 is connected with the high-voltage power supply and a switch K2.

3. The voltage boost circuit of a direct-hanging high voltage power supply as claimed in claim 1, wherein the cathode of said diode D1 is further connected to a switch KS3, and the other end of the switch KS3 is connected to the cathode of the diode D2.

4. A voltage boost circuit of a direct-hanging high voltage power supply according to claim 2, characterized in that one end of said switch K1 is connected with switch KS1, the other end of switch K1 is connected with resistor RS1, and the other end of switch KS1 is connected with the other end of resistor RS 1.

5. A voltage boost circuit of a direct-hanging high voltage power supply according to claim 3, characterized in that one end of said switch K1 is connected with switch KS1, the other end of switch K1 is connected with resistor RS1, and the other end of switch KS1 is connected with the other end of resistor RS 1.