An integrated controller for a PTC heater and a DC / DC converter

Abstract

The present invention discloses an integrated controller for a PTC heater and a DC / DC converter, which includes a PTC heater and a DC / DC converter integrated in the same housing, a low-voltage plug connected to the input ends of the PTC heater and the DC / DC converter, a high-voltage plug connected to the output ends of the PTC heater and the DC / DC converter, and a communication circuit and an information processing unit connected between the low-voltage plug and the high-voltage plug. The PTC heater and the DC / DC converter share the communication circuit and the information processing unit. Compared with the prior art, the present invention integrates the PTC heater and the DC / DC converter, which can not only meet the vehicle heating but also enable the DC / DC converter to provide low-voltage power supply for the vehicle, optimizing the space and reducing the cost.

Description

Technical Field

[0001] The present invention relates to the field of automobiles, and particularly to an integrated controller for a PTC heater and a DC / DC converter. Background Art

[0002] With the demands of energy conservation, emission reduction, carbon neutrality, and carbon peak, new energy vehicles are becoming the new main force in the automotive industry and developing at a high speed. Currently, pure electric vehicles do not have an engine. When the ambient temperature is relatively low, additional heat sources are required for battery pack heating and air conditioning heating. PTC is an ideal heating element.

[0003] In the electric vehicle industry, components are developing towards miniaturization and lightweight. Among them, in-vehicle DC / DC has a set of independent electronic components and a housing, which not only has a high cost but also occupies the overall vehicle space. Even if DC / DC is integrated with the on-vehicle charger OBC, considering functional safety, the DC / DC converter needs to be additionally backed up to meet the reliability requirements of low-voltage power supply.

[0004] Moreover, currently on the market, for a DC / DC converter to have an active discharge function, an additional discharge resistor needs to be added, increasing the cost and volume; at the same time, for a DC / DC converter to have a reverse pre-charge function, a pre-charge resistor needs to be added, making the circuit topology more complex.

[0005] Therefore, how to design an integrated controller for a PTC heater and a DC / DC converter is a technical problem that the industry urgently needs to solve. Summary of the Invention

[0006] Aiming at the problem in the prior art that pure electric vehicles do not have an engine and need additional heat sources, the present invention proposes an integrated controller for a PTC heater and a DC / DC converter.

[0007] The technical solution of the present invention is to propose an integrated controller for a PTC heater and a DC / DC converter, including a PTC heater and a DC / DC converter integrated in the same housing, a low-voltage plug connected to the input ends of the PTC heater and the DC / DC converter, a high-voltage plug connected to the output ends of the PTC heater and the DC / DC converter, and a communication circuit and an information processing unit connected between the low-voltage plug and the high-voltage plug. The PTC heater and the DC / DC converter share the communication circuit and the information processing unit.

[0008] Furthermore, it further includes a switch circuit connected between the PTC heater and the DC / DC converter. The switch circuit controls its on-off state through the information processing unit and switches the DC / DC converter and the PTC heater to work in a series state or a parallel state.

[0009] Further, when the PTC heater and the DC / DC converter are operating in parallel, the integrated controller includes three operating modes:

[0010] The DC / DC operating mode, which is used for the DC / DC converter to operate independently;

[0011] The PTC heating mode, which is used for the PTC heater to operate independently;

[0012] The integrated operating mode, which is used for the DC / DC converter and the PTC heater to operate simultaneously.

[0013] Further, when the PTC heater and the DC / DC converter are operating in series, the integrated controller includes three operating modes:

[0014] The PTC operating mode, which controls the PTC heater to operate through the DC / DC converter;

[0015] The DC / DC reverse pre-charge mode, which is used for the DC / DC converter to operate in reverse, and the PTC heater is short-circuited to act as a pre-charge resistor;

[0016] The DC / DC forward discharge mode, which is used for the DC / DC converter to operate forward, and the PTC heater is short-circuited to charge and discharge the resistor.

[0017] Further, the switch circuit includes switch S1 and switch S2. One end of switch S1 is connected between the DC / DC converter and the high-voltage plug-in, and the other end is connected to the PTC heater. Switch S2 is a single-pole double-throw switch, which has a control end connected to the DC / DC converter, a first contact connected between switch S1 and the PTC heater, and a second contact connected between the high-voltage plug-in and the PTC heater.

[0018] Further, when switch S1 is turned on and the control end of switch S2 is connected to the second contact, the PTC heater and the DC / DC converter are operating in parallel.

[0019] Further, when switch S1 is turned off and the control end of switch S2 is connected to the first contact, the PTC heater and the DC / DC converter are operating in series.

[0020] Further, the switch circuit includes switch S1, switch S3 and switch S4. One end of switch S1 is connected between the DC / DC converter and the high-voltage plug-in, and the other end is connected to the PTC heater. Switch S3 is connected between the DC / DC converter and the PTC heater. One end of switch S4 is connected to the DC / DC converter, and the other end is connected between the high-voltage plug-in and the PTC heater.

[0021] Furthermore, when the switch S1 and the switch S4 are turned on, the PTC heater and the DC / DC converter operate in parallel.

[0022] When the switch S1 is turned off and the switch S3 is turned on, the PTC heater and the DC / DC converter operate in series.

[0023] Furthermore, it further includes an EMC protection circuit disposed in the housing for eliminating external electromagnetic interference and an auxiliary power supply for power supply. The PTC heater and the DC / DC converter share the EMC protection circuit and the auxiliary power supply.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects:

[0025] 1. A integrated controller for a PTC heater and a DC / DC converter is proposed, which can not only meet the vehicle heating but also enable the DC / DC converter to supply low-voltage power to the vehicle. Moreover, the PTC heater and the DC / DC converter share the high-voltage bus terminal, the low-voltage bus terminal, and the heat dissipation channel, which optimizes the space and reduces the design cost.

[0026] 2. Through the control of the switch circuit, the DC / DC active discharge function and the reverse pre-charge function can be satisfied on the basis of the original functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is a connection schematic diagram of the PTC heater of the present invention;

[0029] Figure 2 It is a connection schematic diagram of the DC / DC converter of the present invention;

[0030] Figure 3 、 Figure 4 It is a connection schematic diagram of the integrated controller of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the following further details the present invention with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not used to limit the present invention.

[0032] Thus, a feature pointed out in this specification will be used to illustrate one of the features of an embodiment of the present invention, rather than implying that each embodiment of the present invention must have the illustrated feature. In addition, it should be noted that this specification describes many features. Although some features may be combined to show possible system designs, these features can also be used in other combinations not explicitly described. Thus, unless otherwise stated, the illustrated combinations are not intended to be limiting.

[0033] The principle and structure of the present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

[0034] When an electric vehicle is working, a DC / DC converter is required to provide low-voltage power supply for the whole vehicle. At the same time, when the ambient temperature is relatively low, an additional heat source needs to be set, which makes the design cost of the whole vehicle relatively high and occupies the overall space of the vehicle. The idea of the present invention is to propose an integrated controller for a PTC heater and a DC / DC converter, which can not only meet the heating function of the PTC heater, but also provide low-voltage power supply input through the DC / DC converter.

[0035] Please refer to Figure 3 and Figure 4 , the integrated controller proposed by the present invention includes:

[0036] A DC / DC converter, which is connected between a high-voltage plug and a low-voltage plug and is used for DC / DC conversion. It can convert the high-voltage electricity output by the high-voltage plug into the low-voltage electricity required by the vehicle.

[0037] A PTC heater (PTC load in the figure), which is connected to the high-voltage plug and the low-voltage plug and is used to provide a heat source for the whole vehicle.

[0038] A switch circuit, which is connected to the DC / DC converter and the PTC heater, and the working mode of the integrated controller can be switched by controlling the on / off state of the switch circuit.

[0039] An information processing unit, which is used to control the switch state of the switch circuit, and thus adjust the working state of the integrated controller.

[0040] Specifically, a communication circuit is connected between the information processing unit and the low-voltage plug, and a drive circuit is connected between the information processing unit and the switch circuit. The communication circuit is used to receive an external power command and transmit it to the information processing unit. After receiving the power command, the information processing unit converts it into a control signal for the switch circuit, and controls the drive circuit to adjust the working state of the switching tube in the switch circuit according to the control signal, thereby switching the working state of the integrated controller.

[0041] Among them, the PTC heater and the DC / DC converter are integrated in the same housing and share a communication circuit and an information processing unit, further optimizing the space and saving costs.

[0042] Furthermore, according to the switching state of the switching circuit, the DC / DC converter and the PTC heater can be switched between the series state and the parallel state.

[0043] When the DC / DC converter and the PTC heater work in parallel, according to the working principle of the parallel circuit, at this time the DC / DC converter and the PTC heater work independently of each other. At this time, the integrated controller can work in three modes, namely:

[0044] DC / DC working mode. In this mode, the DC / DC converter works alone and can be used to provide a low-voltage power supply demand for the whole vehicle.

[0045] PTC heating mode. In this mode, the PTC heater works alone and can be used to heat the whole vehicle.

[0046] Integrated working mode. In this mode, the PTC heater and the DC / DC converter work simultaneously. At this time, it can not only heat the whole vehicle but also meet the low-voltage power supply demand of the whole vehicle.

[0047] Please refer to Figure 1 and Figure 2 , when the DC / DC converter and the PTC heater are in parallel, the two work independently of each other, so they can be regarded as two circuits respectively. Figure 1 is a connection schematic diagram of the PTC heater. As can be seen from Figure 1 , it has a communication circuit, an information processing unit (the high- and low-voltage isolation information processing unit in the figure), an auxiliary power supply (the isolated auxiliary power supply in the figure), and an EMC protection circuit (the EMC and interface protection circuit in the figure). It is connected between the low-voltage plug and the high-voltage plug together with the PTC heater. Figure 2 is a connection schematic diagram of the DC / DC converter. As can be seen from Figure 2 , it has a communication circuit, an information processing unit, an auxiliary power supply (the isolated auxiliary power supply in the figure), and an EMC protection circuit (the EMC and interface protection circuit in the figure). It is connected to the low-voltage plug and the high-voltage plug together with the DC / DC converter. By Figure 1 and Figure 2From the analysis, it can be seen that for the connection schematic diagram of the PTC heater and the connection schematic diagram of the DC / DC converter, both have an information processing unit, a communication circuit, an auxiliary power supply, and an EMC protection circuit. In the present invention, this part of the components is used as the common part of the two in the integrated controller. That is, through the design of the present invention, at least the design of one communication circuit, information processing unit, auxiliary power supply, and EMC protection circuit is saved, reducing the design cost and volume of the device.

[0048] Furthermore, the DC / DC converter and the PTC heater also share a heat dissipation channel, enabling the heat generated by the DC / DC to provide a heat source for heating the whole vehicle at the same time, reducing the energy consumption of the PTC heater and the overall volume of the device.

[0049] When the DC / DC converter and the PTC heater are operating in series, the operation of the DC / DC converter will be affected by the PTC heater at this time. When the PTC heater is not working, it can be regarded as a resistor as a whole, and this resistor can be used as the pre-charge resistor or discharge resistor of the DC / DC converter.

[0050] Specifically, in this state, the integrated controller has three working modes, namely:

[0051] PTC working mode. In this mode, the PTC heater is in the working state and it works through the DC / DC converter controller.

[0052] DC / DC reverse pre-charge mode. In this mode, the PTC heater is not working and it is equivalent to a resistor. At this time, the DC / DC controller is in the reverse pre-charge state, and the PTC heater is used as the pre-charge resistor for reverse pre-charge.

[0053] DC / DC forward discharge mode. In this mode, the PTC heater is not working and it is equivalent to a resistor. At this time, the DC / DC controller is in the forward discharge state, and the PTC heater is used as the discharge resistor for forward discharge.

[0054] It can be seen that by adjusting the switch state of the switch circuit, the integrated controller can enable the DC / DC converter to have the reverse pre-charge function and the active discharge function while meeting the low-voltage power supply requirements of the whole vehicle and the heating requirements of the whole vehicle, without adding additional circuits and costs to the circuit.

[0055] Specifically, please refer to Figure 4 , the switch circuit includes switch S1 and switch S2. One end of switch S1 is connected between the DC / DC converter and the high-voltage plug-in, and the other end is connected to the PTC heater. Switch S2 is a single-pole double-throw switch, which has a control end connected to the DC / DC converter, a first contact A connected between switch S1 and the PTC heater, and a second contact B connected between the high-voltage plug-in and the PTC heater.

[0056] Among them, when the switch S1 is turned on and the control end of the switch S2 is connected to the second contact B, the current flowing through the DC / DC converter cannot flow into the PTC heater through the switch S2 at this time, and the DC / DC controller and the PTC heater operate in parallel. When the switch S1 is turned off and the control end of the switch S2 is connected to the first contact A, the current flowing through the DC / DC converter will flow into the PTC heater through the first contact A of the switch S2 at this time, and the DC / DC controller and the PTC heater operate in series. In the present invention, the information processing unit controls the driving circuit to adjust the switching state of the switching tube in the switching circuit according to the external power command received by the communication circuit. This external power command can be input according to user needs. For example, when it is necessary to simultaneously meet the low-voltage power supply and heating requirements of the whole vehicle, the PTC heater and the DC / DC controller are made to be in a parallel state by controlling the switching circuit, and the PTC heater and the DC / DC controller work simultaneously. Thus, through the design of the present invention, the control requirements of users in various scenarios can be met.

[0057] In other embodiments of the present invention, the single-pole double-throw switch S2 can be replaced by switches S3 and S4. The specific connection is that one end of the switch S1 is connected between the DC / DC converter and the high-voltage plug-in, and the other end is connected to the PTC heater. The switch S3 is connected between the DC / DC converter and the PTC heater, and one end of the switch S4 is connected to the DC / DC converter, and the other end is connected between the high-voltage plug-in and the PTC heater.

[0058] Among them, when the switches S1 and S4 are turned on, the current flowing through the DC / DC converter cannot flow into the PTC heater at this time, and the DC / DC controller and the PTC heater operate in parallel. When the switch S1 is turned off and the switch S3 is turned on, the current flowing through the DC / DC converter will flow into the PTC heater through the switch S3 at this time, and the DC / DC controller and the PTC heater operate in series. The switching states of both switches are controlled by the information processing unit controller, so as to meet the control requirements of users in various scenarios.

[0059] Further, please refer to Figure 2, the DC / DC converter proposed by the present invention includes a switching transistor SR1, a switching transistor SR2, an inductor Lf, a capacitor Co, a switching transistor Q1, a switching transistor Q2, a switching transistor Q3, a switching transistor Q4, a capacitor Chv, and a transformer T. One end of the switching transistor SR2 is connected to the positive output terminal of the low-voltage plug-in, and the other end is connected to the first end of the primary winding of the transformer T. One end of the switching transistor SR2 is connected between the switching transistor SR1 and the positive output terminal of the low-voltage plug-in, and the other end is connected to the second end of the primary winding of the transformer T. One end of the inductor Lf is connected to the center tap of the primary winding of the transformer T, and the other end is connected to the negative output terminal of the low-voltage plug-in. The capacitor Co is connected in parallel across the low-voltage plug-in.

[0060] The switching transistors Q1, Q2, Q3, and Q4 form a full-bridge circuit. The switching transistor Q4 is the upper arm of the first bridge arm, the switching transistor Q3 is the lower arm of the first bridge arm, the switching transistor Q2 is the upper arm of the second bridge arm, and the switching transistor Q1 is the lower arm of the second bridge arm. The first end of the secondary winding of the transformer T is connected to the midpoint of the first bridge arm, and the second end is connected to the midpoint of the second bridge arm. The capacitor Chv is connected in parallel across the high-voltage plug-in.

[0061] It should be noted that Figure 2 only one of the topological structures is pointed out, but the topological structure of the present invention is not limited to the above embodiments. Any improvement to the DC / DC converter circuit topology that satisfies the DC / DC conversion should fall within the protection scope of the present invention.

[0062] Furthermore, the integrated controller proposed by the present invention further includes an EMC protection circuit connected to the DC / DC converter. Since the integrated device is both a device vulnerable to noise interference and a noise source for external interference, the EMC protection circuit can, on the one hand, filter out external electromagnetic interference from low voltage to high voltage, and on the other hand, prevent the device itself from radiating noise interference to affect other electronic products, thus ensuring the safety of personnel and equipment.

[0063] In the present invention, the signal processing unit is connected between the low-voltage plug-in and the high-voltage plug-in and can also be used to isolate low-voltage signals and high-voltage signals.

[0064] In other embodiments of the present invention, an auxiliary power supply for power supply is also integrated in the housing. The DC / DC converter and the EMC protection circuit share the auxiliary power supply, which further saves space and reduces costs while meeting the power supply requirements.

[0065] Compared with the prior art, the integrated controller proposed by the present invention integrates a DC / DC converter and a PTC heater, which not only meets the low-voltage power supply demand and heating requirement of the whole vehicle, but also reduces the volume and cost of the whole vehicle. At the same time, by adjusting the switch state in the switching circuit, the present invention also has a reverse pre-charging function and a forward charging function, enabling the circuit not to require additional circuitry, which also reduces the cost of the circuit to a certain extent.

[0066] The above embodiments are only used to illustrate the specific implementation manners of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and changes can still be made, and these deformations and changes should all fall within the protection scope of the present invention.

Claims

1. An integrated controller for a PTC heater and a DC / DC converter, characterized in that, It includes a PTC heater and a DC / DC converter integrated in the same housing, a low-voltage plug connected to the input ends of the PTC heater and the DC / DC converter, a high-voltage plug connected to the output ends of the PTC heater and the DC / DC converter, and a communication circuit and an information processing unit connected between the low-voltage plug and the high-voltage plug. The PTC heater and the DC / DC converter share the communication circuit and the information processing unit.

2. The integrated controller according to claim 1, wherein It further includes a switch circuit connected between the PTC heater and the DC / DC converter. The switch circuit controls its switch state through the information processing unit and switches the DC / DC converter and the PTC heater to work in a series state or a parallel state.

3. The integrated controller according to claim 2, wherein, When the PTC heater and the DC / DC converter work in a parallel state, the integrated controller includes three working modes: The DC / DC working mode, which is used for the DC / DC converter to work alone; The PTC heating mode, which is used for the PTC heater to work alone; The integrated working mode, which is used for the DC / DC converter and the PTC heater to work simultaneously.

4. The integrated controller according to claim 2, wherein When the PTC heater and the DC / DC converter work in a series state, the integrated controller includes three working modes: The PTC working mode, which controls the PTC heater to work through the DC / DC converter; The DC / DC reverse pre-charge mode, which is used for the DC / DC converter to run in reverse, and the PTC heater is short-circuited to act as a pre-charge resistor; The DC / DC forward discharge mode, which is used for the DC / DC converter to run forward, and the PTC heater is short-circuited to charge and discharge the resistor.

5. The integrated controller according to claim 2, wherein, The switch circuit includes switch S1 and switch S2. One end of switch S1 is connected between the DC / DC converter and the high-voltage plug, and the other end is connected to the PTC heater. Switch S2 is a single-pole double-throw switch, which has a control end connected to the DC / DC converter, a first contact connected between switch S1 and the PTC heater, and a second contact connected between the high-voltage plug and the PTC heater.

6. The integrated controller according to claim 5, characterized in that, When switch S1 is turned on and the control end of switch S2 is connected to the second contact, the PTC heater and the DC / DC converter work in a parallel state.

7. The integrated controller according to claim 5, characterized in that When switch S1 is turned off and the control end of switch S2 is connected to the first contact, the PTC heater and the DC / DC converter work in a series state.

8. The integrated controller according to claim 2, wherein The switch circuit includes switch S1, switch S3 and switch S4. One end of switch S1 is connected between the DC / DC converter and the high-voltage plug, and the other end is connected to the PTC heater. Switch S3 is connected between the DC / DC converter and the PTC heater. One end of switch S4 is connected to the DC / DC converter, and the other end is connected between the high-voltage plug and the PTC heater.

9. The integrated controller according to claim 8, wherein When switch S1 and switch S4 are turned on, the PTC heater and the DC / DC converter work in a parallel state; When switch S1 is turned off and switch S3 is turned on, the PTC heater and the DC / DC converter work in a series state.

10. The integrated controller according to claim 1, wherein, It further includes an EMC protection circuit disposed in the housing for eliminating external electromagnetic interference and an auxiliary power supply for power supply. The PTC heater shares the EMC protection circuit and the auxiliary power supply with the DC / DC converter.

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