Heating device

Abstract

To provide a heating device enabling stable operation by suppressing unevenness in time required to reach heater output and target power consumption even when a voltage range applied to the heating device is a wide band.SOLUTION: A heating device 10 includes: an electric resistance element 11 capable of generating heat in response to a power consumption demand from a vehicle; and control means 13 capable of controlling at least power consumption by the electric resistance element 11. The control means 13 can adjust a rise amount of the power consumption in a predetermined reference time in response to an applied voltage to the electric resistance element 11.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a heating device for a vehicle.

Background Art

[0002] Conventionally, as a vehicle air conditioner, a heating device (heat medium heating device) that heats a heat medium circulating through an air conditioning heat exchanger (heater core) is known (see, for example, Patent Document 1).

[0003] In particular, in an EV vehicle or a hybrid vehicle, a vehicle air conditioning system that uses a heater of a heating device as a heating function in an air conditioner and as a load that consumes regenerative power generated by regeneration is also known (see, for example, Patent Document 2).

[0004] In the case of a heating device adopted in an EV vehicle, a hybrid vehicle, etc., a DC power source for supplying power to the heating device is generally a power storage device (battery) mounted on the vehicle. In this case, when the voltage of the power storage device increases in next-generation vehicles, the voltage range applied to the heating device will also cover a wide band accordingly.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, when the voltage range applied to the heating device covers a wide band, there is a problem that it becomes difficult to stabilize the time until the heater output and the target power consumption are reached.

[0007] Specifically, when the voltage applied to the heating device was in a relatively low voltage range (for example, around 120V to 450V), general-purpose control of the heater drive (including control from off to on, and control to increase power consumption) was possible using a single control parameter.

[0008] However, in next-generation vehicles, if the voltage applied to the heating device extends beyond the low-voltage range to a wide range of high voltages (for example, around 120V to 800V), using the control parameters that were used in the conventional low-voltage range (around 120V to 450V) in the high-voltage range (for example, high voltages exceeding 500V) will result in a hunting phenomenon where the heater output fluctuates around the target power consumption (set value), and does not converge.

[0009] Furthermore, when using different control parameters suitable for high-voltage operation, the time it takes to reach the target power consumption (time to reach target power consumption) increases significantly when low voltage is applied. In some cases, depending on the applied voltage (for example, at low voltage), the time to reach the target power consumption may be very long. In particular, there are many situations where it is desirable to reach the target power consumption in a short time, such as for the purpose of regenerative power consumption or air conditioning (heating) in cold weather. Therefore, it is desirable to prevent delays in the time to reach the target power consumption and to reduce the variation in the time to reach the target power consumption depending on the applied voltage.

[0010] In view of these circumstances, the present invention aims to provide a heating device that can operate stably by suppressing variations in heater output and the time it takes to reach the target power consumption, even when the voltage range applied to the heating device is wideband. [Means for solving the problem]

[0011] The present invention comprises an electrical resistance element capable of generating heat in response to power consumption requests from a vehicle, and a control means capable of at least controlling the power consumption of the electrical resistance element. An upper switching element and a lower switching element connected in series via the aforementioned electrical resistance element, A heating device comprising, the control means, The upper switching element and the lower switching element can be controlled to open and close.The amount of increase in power consumption over a predetermined reference time can be adjusted according to the voltage applied to the electrical resistance element. the law of nature , The predetermined reference time is a predetermined control cycle that includes at least the switching control, and for each predetermined control cycle, the amount of operation for the switching control in the next control cycle is calculated according to the difference between the target power consumption in the current control cycle and the power consumption of the electrical resistance element, the amount of increase is adjusted, and parameter switching control is performed to calculate the amount of operation for the switching control for each predetermined control cycle by switching between a low-voltage parameter when the applied voltage is lower than the threshold voltage and a high-voltage parameter when the applied voltage is higher than the threshold voltage, according to the applied voltage. This relates to a heating device characterized by the following features. [Effects of the Invention]

[0012] According to the present invention, even when the voltage range applied to the heating device is wideband, it is possible to suppress variations in heater output and the time it takes to reach the target power consumption, thereby providing a heating device that can operate stably, which is an excellent effect. [Brief explanation of the drawing]

[0013] [Figure 1] This figure shows the configuration of the heating device of the present invention, and includes (A) an overview block diagram, (B) a plan view showing the general configuration of the device, and (C) a side view showing the general configuration of the device. [Figure 2] This is a circuit diagram showing the control and drive means of the heating device of the present invention. [Figure 3] This is a functional block diagram illustrating the heating device of the present invention. [Figure 4] The diagrams illustrate voltage control in the heating device of the present invention, with (A) to (D) showing the change in duty cycle when a predetermined program processing is performed for a predetermined period in the low-speed start processing unit, (E) showing an example of the change over time of the output (power) of an electrical resistance element by the same low-speed start processing unit, (F) and (G) showing the change in duty cycle when a predetermined program processing is performed for a predetermined period in the high-speed start processing unit, (H) showing an example of the change over time of the output (power) of an electrical resistance element by the same high-speed start processing unit, and (I) to (J) showing an example of the change over time of the output (power) of an electrical resistance element when the low-speed start processing unit and the high-speed start processing unit are superimposed. [Figure 5] This is a flowchart showing the flow of heater control processing in the heating device of the present invention. [Figure 6] This is a flowchart showing the flow of the heater drive control process in the heating device of the present invention. [Figure 7] This is a conceptual diagram illustrating the method for calculating the duty cycle and duty cycle amount in the heating device of the present invention. [Figure 8] This graph shows the relationship between the time required to reach the target power consumption and the applied voltage in the heating device of the present invention. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described below with reference to the accompanying drawings. Figures 1 to 8 are examples of embodiments of the present invention, and parts with the same reference numerals in the figures represent the same components. In addition, some components are omitted in each figure to simplify the drawings. Also, the shape and dimensions of some components in each figure are exaggerated as appropriate.

[0015] <Overall configuration of the heating device> Figure 1 is a diagram illustrating the heating device 10 of this embodiment. Figure 1(A) is a block diagram showing an overview of the heating device 10, Figure 1(B) is a plan view showing a schematic of the configuration of the heating device 10, and Figure 1(C) is a side view showing a schematic of the configuration of the heating device 10.

[0016] As shown in Figure 1(A), the heating device 10 of this embodiment constitutes, for example, a part of a vehicle air conditioning system S. The heating device 10 is a heat transfer medium heating device that heats the heat transfer medium Hm that circulates through the air conditioning heat exchanger (heater core) in the vehicle air conditioning system 21. The vehicle in which the heating device 10 of this embodiment is installed is, for example, an EV or a hybrid vehicle, and has a regenerative braking device 4, which is configured to store the regenerative power generated when the regenerative braking device 4 is braking in a power storage device 6. The power storage device 6 is a DC power source that supplies power to the heating device 10.

[0017] In this vehicle air conditioning system, the heating device 10 is used for two purposes: to consume electricity for heating the air inside the vehicle in the vehicle air conditioning system 21 (air conditioning use), and to consume surplus electricity when the regenerated power exceeds the amount of electricity stored in the energy storage device 6 (surplus power consumption use).

[0018] In other words, the heating device 10 receives a request for power consumption as air heating in the vehicle air conditioning system 21 (hereinafter also referred to as "air conditioning power consumption request"), which is transmitted based on the control of the vehicle air conditioning system 21, and a request for power consumption as surplus power consumption when the regenerative power generated by the regenerative system 4 during braking exceeds the amount of energy stored in the energy storage system 6 (hereinafter also referred to as "surplus power consumption request"), and heats the heat transfer medium Hm based on these requests. In the following description of this embodiment, unless it is necessary to distinguish between the air conditioning power consumption request and the surplus power consumption request, both will be collectively referred to as "power consumption request". A power consumption request is a request signal that includes at least information (requested value) corresponding to the amount of power to be consumed.

[0019] In the example shown in Figure 1(A), the source of the air conditioning power consumption request is the control unit (ECU) of the vehicle air conditioning system 21, and the source of the surplus power consumption request is, for example, the control unit (ECU) of a charge control device 22 that monitors and controls the regenerative braking system 4 and / or the energy storage system 6. These are connected to the heating device 10 by a wired or wireless communication line.

[0020] Detailed illustrations of the ECU of the vehicle air conditioning system 21 (hereinafter referred to as the air conditioning ECU1) and the ECU of the charging control device 22 (hereinafter referred to as the charging ECU2) are omitted, but each includes a CPU (Central Processing Unit), memory such as ROM (Read Only Memory) or RAM (Random Access Memory), a non-volatile storage unit such as an HDD (Hard Disk Drive) or SSD (Solid State Drive), and a communication control unit. The CPU, memory, storage unit, and communication control unit are connected to each other via an internal bus so that they can communicate with one another. The communication control unit is connected to the heating device 10 by a communication line and is capable of transmitting information (signals) such as power consumption requests to the heating device 10.

[0021] As shown in Figures 1(A) to 1(C), the heating device 10 includes, for example, electrical resistance elements 11 (11A, 11B), a driving means 12 for the electrical resistance elements 11, a control means (control unit) 13, a request acquisition means 14, and various sensors (not shown). The electrical resistance elements 11 generate heat when energized in response to multiple power consumption requests transmitted from a computer mounted on the vehicle, and constitute the heater of the heating device 10. In the following description and drawings, the term "heater" may be used, but this refers to the electrical resistance elements 11.

[0022] The driving means 12 (heater driving means 12) for the electrical resistance element 11, the control means 13, and the request acquisition means 14 are arranged on the control board 1 as electronic components. The control means 13 consists of an arithmetic unit (e.g., CPU) and storage means (volatile memory (RAM, ROM) or non-volatile storage means (HDD, SSD)). The control means 13 holds various programs in the storage means and executes these programs or various calculations to comprehensively control each part (each component) of the heating device 10. The control means 13 may also be the ECU of the heating device 10.

[0023] In this example, the request acquisition means 14 includes a communication means 19 that communicates with the air conditioning ECU 1 and the charging ECU 2, and is a means for receiving power consumption requests and various other requests from the air conditioning ECU 1 and the charging ECU 2.

[0024] As will be described in more detail later, as shown in Figures 1(B) and 1(C), the heater driving means 12 includes switching elements 121 and 122 and their drivers (not shown in Figure 1). The control means 13 controls the opening and closing of the switching elements 121 and 122 to control the conduction and interruption of the electrical resistance element 11.

[0025] The electrical resistance element 11 and the control board 1 are housed in a case 2, and the case 2 is provided with pipes 3 that connect its interior and exterior. Two pipes 3 are provided, forming an inlet 3A and an outlet 3B, and their interiors serve as passages for the heat transfer medium Hm. The heat transfer medium Hm is, for example, water, but may also be coolant or oil. As shown in Figure 1(C), the case 2 consists of an upper case 2A and a lower case 2B, each having a heater housing recess 21, and the electrical resistance element 11 is housed in the heater housing space 22 formed by combining these two cases.

[0026] The power supply unit 5 has a power supply terminal 5A, and the power supply terminal 5A and the control board 1 are connected by wiring (not shown). Power from the energy storage device 6 is supplied to the power supply unit 5. The voltage applied to the power supply unit 5 is, for example, 100V to 1000V (preferably, for example, 120V to 800V).

[0027] With this configuration, the heating device 10 energizes the electrical resistance element 11 with power from the energy storage device 6 based on power consumption requests from the air conditioning ECU 1 and the charging ECU 2, causing it to generate heat. This consumes power equivalent to the amount of heat generated.

[0028] Figure 2 is a circuit block diagram showing an example of the heater driving means 12 and control means 13 of the heating device 10.

[0029] The heater driving means (heater driving circuit) 12 includes, for example, an upper switching element 121, a lower switching element 122, an upper driver 123, a lower driver 124, an upper capacitor 125, a lower capacitor 126, and so on.

[0030] Both the upper switching element 121 and the lower switching element 122 are, for example, voltage-driven transistors. More specifically, they are insulated-gate field-effect transistors in which an n-channel is formed by applying a positive gate voltage to the low-potential terminal, and specifically, for example, they are insulated-gate bipolar transistors (IGBTs).

[0031] For the sake of explanation, the upper switching element 121 will be referred to as the upper IGBT 121, and the lower switching element 122 as the lower IGBT 122. The upper IGBT 121 and the lower IGBT 122 are connected in series via the electrical resistance element 11. The high-potential side terminal (collector) of the upper IGBT 121 is connected to the positive terminal of the high-voltage power supply 131, and the low-potential side terminal (emitter) is connected to the high-potential side terminal of the electrical resistance element 11. In addition, the low-potential side terminal of the electrical resistance element 11 is connected to the high-potential side terminal (collector) of the lower IGBT 122, and the low-potential side terminal (emitter) of the lower IGBT 122 is connected to the negative terminal of the high-voltage power supply 131. In this case, the high-voltage power supply 131 is the power supply unit 5 shown in Figure 1(B). In other words, depending on the charge storage state of the energy storage device 6, the high-voltage power supply 131 supplies a wide range (broadband) voltage of 100V to 1000V (preferably 120V to 800V) to the electrical resistance element 11. To put it another way, the voltage applied to the electrical resistance element 11 fluctuates depending on the charge storage state of the energy storage device 6.

[0032] The upper-layer driver 123 is a circuit that applies a gate-emitter voltage to the gate terminal of the upper-layer IGBT 121 based on a driver drive signal input from the control means 13. The lower-layer driver 124 is a circuit that applies a gate-emitter voltage to the gate terminal of the lower-layer IGBT 122 based on a driver drive signal input from the control means 13.

[0033] The power input terminal of the upper layer driver 123 is connected to the driver power supply 130 via the upper layer capacitor 125. This upper layer capacitor 125 is a bootstrap capacitor that stores charge to open (turn on) the upper layer IGBT 121. The power input terminal of the lower layer driver 124 is connected to the driver power supply 130 via the lower layer capacitor 126.

[0034] The control means 13 is capable of controlling the heater drive means 12 (heater drive control). Specifically, the control means 13 is capable of controlling the opening (on) / closing (off) of the upper IGBT 121 and the lower IGBT 122 (opening / closing control). By performing this opening / closing control, conduction / interruption is performed to the electrical resistance element 11, and as a result, the power consumption by the electrical resistance element 11 can be controlled to some extent. In this embodiment, for example, the voltage applied to the upper IGBT 121 and the lower IGBT 122 is controlled using a PWM (Pulse Width Modulation) method to control the opening and closing of the upper IGBT 121 and the lower IGBT 122.

[0035] More specifically, the control means 13 supplies driver drive signals with pulse waveforms that have different timings to the driver drive signal input terminals of the upper driver 123 and the lower driver 124, respectively. The upper driver 123 outputs a pulse waveform voltage to the gate of the upper IGBT 121 in synchronization with the driver drive signal, which is equivalent to the voltage obtained by adding the voltage of the high-voltage power supply 131 to the gate-emitter voltage of the upper IGBT 121 itself. The lower driver 124 outputs a pulse waveform voltage to the gate of the lower IGBT 122 in synchronization with the driver drive signal supplied from the control means 13, which is equivalent to the voltage of the driver power supply 130.

[0036] As a result, the channels of the upper IGBT 121 and the lower IGBT 122 are opened (on) and closed (off) at predetermined timings. During the period when the upper IGBT 121 and the lower IGBT 122 are both turned on, the electrical resistance element 11 is energized, and power is consumed due to the heat generated.

[0037] Thus, the control means 13 can control the electrical resistance element 11 to consume power and increase its power consumption based on the power consumption request from the vehicle. Furthermore, as will be described in detail later, the control means 13 can adjust the degree of increase (amount of increase) of the power consumption of the electrical resistance element 11 at a predetermined reference time, according to the voltage applied to the electrical resistance element 11 (a voltage of 100V to 1000V depending on the state of the energy storage device 6). In this case, the "predetermined reference time" is, for example, a predetermined control period by the control means 13, for example, a predetermined control period that includes the switching control of the upper IGBT 121 and the lower IGBT 122. More specifically, in this embodiment, the heater drive means 12 can perform heater drive control including the switching control (e.g., PWM control) of the upper IGBT 121 and the lower IGBT 122, and the "predetermined reference time" is the control period of said heater drive control (e.g., a period based on the frequency that determines the pulse width modulation period (e.g., 57Hz)).

[0038] The heater driving means 12 can be any circuit that drives (energizes and stops) the electrical resistance element 11 by switching the upper IGBT 121 and the lower IGBT 122 on and off. In addition to the configuration shown in Figure 2, the heating device 10 of this embodiment may have a known configuration (for example, a diode) as a circuit that properly drives the electrical resistance element 11, the upper IGBT 121, and the lower IGBT 122.

[0039] <Functions of the heating device> Figure 3 is a block diagram illustrating an example of the function of the heating device 10 in this embodiment. As already mentioned, the heating device 10 receives power consumption requests from at least an external source (vehicle) (air conditioning power consumption requests and surplus power consumption requests), and based on these requests, energizes the electrical resistance element 11 to heat the heat transfer medium Hm.

[0040] This heating device 10 has, for example, a forced shutoff function, a request acquisition function, a request determination function, a start processing determination function, and a power control function. These functions are realized by the physical means of the heating device 10 shown in Figures 1 and 2 (hardware such as electronic components (circuits and elements) provided on the control board 1) and the execution of software (programs) of the control means 13.

[0041] Figure 3 is a block diagram illustrating the heating device 10 from the perspective of the means for realizing the above functions. The heating device 10 includes, for example, a forced shut-off means 20, a request acquisition means 14, a request determination means 15, a start processing determination means 16, and a power control means 17. These are realized, for example, by various electronic components arranged on one or more control boards 1, and are comprehensively controlled by a control means 13. In other words, some or all of these means include the control means 13.

[0042] <<Forced Interruption Measures>> The forced shutdown means 20 implements a forced shutdown function and, based on predetermined conditions (forced shutdown conditions), determines whether the forced shutdown conditions are met and forcibly prohibits power consumption by the electrical resistance element 11. The meeting of the forced shutdown conditions means, for example, that an abnormality has occurred in the heating device 10, specifically, for example, that (1) a protection / fault sensor has detected something, or (2) the overvoltage sensor has not completed fault detection. The heating device 10 has a protection / fault sensor (not shown) that detects a fault in the control board 1 when the control board 1 exceeds the allowable temperature of the electrical resistance element 11 or the upper IGBT 121 and lower IGBT 122. "Detection by the protection / fault sensor" means a state in which the electrical resistance element 11 cannot be operated safely. The forced shutdown means 20 determines that the forced shutdown conditions are met if at least one of the above conditions (1) or (2) is met, and forcibly prohibits power consumption by the electrical resistance element 11 (heater heating) regardless of whether there is a power consumption request.

[0043] <<Request acquisition means>> The request acquisition means 14 implements the request acquisition function and, in this example, includes a communication means 19 that communicates with the air conditioning ECU 1 and the charging ECU 2. It is a receiving means that receives various requests, including air conditioning power consumption requests from the air conditioning ECU 1 and surplus power consumption requests from the charging ECU 2.

[0044] During its operation, the heating device 10 repeatedly performs the heater control process described later at a predetermined cycle (for example, 2 msec), and the request acquisition means 14 detects the reception result of the communication means 19 at each cycle of the heater control process and acquires the power consumption request.

[0045] Alternatively, the control means 13 may, for example, execute interrupt processing (hardware interrupt, and / or software interrupt, or external interrupt, and / or timer interrupt) at a predetermined timing (interrupt cycle), acquire a power consumption request through the interrupt processing, and store it in a predetermined memory area. The request acquisition means 14 may then be configured to acquire the power consumption request from the said memory area at each cycle of the heater control processing.

[0046] Power consumption requests (air conditioning power consumption requests and surplus power consumption requests) are control commands for the heating device 10 and are acquired at all times while the heating device 10 is operating (while heater control processing is being executed). In other words, even if there are no actual power consumption requests, a request (command) for "no request value" is acquired. Here, "no request value" means, for example, that the request value is "less than the minimum request threshold," and the minimum request threshold is 200W as an example. The request value is information that indicates (corresponding to) the actual amount of heat generated (power consumption) of the electrical resistance element 11, but in this embodiment, for the sake of explanation, it will be described as the same numerical value as the amount of heat generated.

[0047] <<Request determination means>> The request determination means 15 implements the request determination function and, based on the power consumption request acquired by the request acquisition means 14, determines whether there is an actual power consumption request. If it is determined that "there is a power consumption request", it sets the request value included in the request as the target value of the actual power consumption (target power consumption G).

[0048] As described above, if there is no actual power consumption request, a power consumption request with a request value of "0 (W)" is obtained and the request determination means 15 determines that "there is no power consumption request". Also, if the request value is less than the minimum request threshold, the request determination means 15 determines that "there is no power consumption request".

[0049] Furthermore, the request acquisition means 14 may acquire multiple power consumption requests (for example, an air conditioning power consumption request and a surplus power consumption request) almost simultaneously. In this case, the request determination means 15 sets the maximum value among the request values ​​included in the multiple power consumption requests as the target value of the actual power consumption (target power consumption G). This prevents a shortage of the request value (target power consumption G) from occurring, for example, when a larger request value is overwritten by a smaller request value.

[0050] Here, even if there is a "power consumption request," if the above-mentioned forced shutdown condition is met, power consumption is forcibly prohibited by the forced shutdown means 20. In other words, "heater off" in this embodiment, that is, the state in which no current is supplied to the electrical resistance element 11, can occur either when the "requested value is less than the minimum required threshold" or when the forced shutdown condition is met.

[0051] <<Start Processing Determination Means>> The start processing determination means 16 implements a start processing determination function, for example, as part of the heater driving means 12. Specifically, the start processing determination means 16 is a means for determining the speed (or degree) at which to increase the current supplied to the electrical resistance element 11 (starting from a disconnected state (increase from a state where no current is supplied)) in response to the acquired power consumption request.

[0052] The power control means 17 (control means 13), described later, includes a high-speed start processing unit 171 and a low-speed start processing unit 172. The high-speed start processing unit 171 is a means for controlling the opening and closing of the upper IGBT 121 and the lower IGBT so that the target power consumption G (determined required value) is reached relatively quickly (in a short time) when the current supplied to the electrical resistance element 11 is increased.

[0053] Furthermore, the low-speed start processing unit 172 is a means for controlling the opening and closing of the upper IGBT 121 and the lower IGBT 122 so that the target power consumption G (determined required value) is reached at a slower speed (over a longer period of time) than the high-speed start processing unit 171 when the current supply to the electrical resistance element 11 is increased.

[0054] The start processing determination means 16 determines, based on predetermined determination conditions, whether to process the acquired power consumption request using the high-speed start processing unit 171 or the low-speed start processing unit 172. One example of a predetermined determination condition is a predetermined start processing determination flag included in the power consumption request. For example, a "high-speed flag" can be set in the power consumption request to indicate that high-speed start processing should be performed. If the start processing determination means 16 determines that the high-speed flag is valid (on, set, "1", etc.), processing is performed by the high-speed start processing unit 171. If the high-speed flag is invalid (off, not set, "0", etc.), processing is performed by the low-speed start processing unit 172.

[0055] For example, the high-speed flag is enabled in the case of surplus power consumption requests where early power consumption is generally desired, and disabled in the case of air conditioning power consumption requests. Alternatively, the high-speed flag may be enabled even in the case of air conditioning power consumption requests. With such a configuration, for example, when it is desired to heat the air inside the vehicle quickly due to a low outside temperature, the slope of the output power can be increased steeply, thereby accelerating the rise in temperature inside the vehicle.

[0056] By making it possible to select between control by the high-speed start processing unit 171 and control by the low-speed start processing unit 172 (and not relying solely on control by the high-speed start processing unit 171), it is possible to prevent excessive load from being placed on the heating device 10.

[0057] <<Power control means>> The power control means 17 implements a power control function, for example, as part of the heater drive means 12, and controls the voltage applied to the upper IGBT 121 and the lower IGBT 122, thereby controlling the conduction to the electrical resistance element 11. The power control means 17 controls the voltage, for example, using a PWM method. That is, according to the required power, it controls the voltage applied to the gates of the upper IGBT 121 and the lower IGBT 122 using PWM control, thereby controlling the opening and closing of the upper IGBT 121 and the lower IGBT 122.

[0058] Furthermore, the power control means 17 includes, for example, a high-speed start processing unit 171 and a low-speed start processing unit 172. Based on the determination result of the start processing determination means 16, the power control means 17 distributes the received power consumption request to either the high-speed start processing unit 171 or the low-speed start processing unit 172.

[0059] When increasing the current supplied to the electrical resistance element 11 (power consumption), the high-speed start processing unit 171 sets the PWM control parameters so that the target power consumption G is reached in a short time from the start of the increase (start of PWM control), or the average rate of increase in power consumption is high, and controls the opening and closing of the upper IGBT 121 and the lower IGBT. Similarly, when increasing the current supplied to the electrical resistance element 11, the low-speed start processing unit 172 sets the PWM control parameters so that the target power consumption G is reached in a longer time from the start of the increase than the high-speed start processing unit 171, or the average rate of increase in power consumption is lower than that of the high-speed start processing unit 171, and controls the opening and closing of the upper IGBT 121 and the lower IGBT 122.

[0060] Furthermore, the power control means 17 includes, at least in the high-speed start processing unit 171, a means (parameter switching means, parameter switching function) for switching control parameters (PWM control parameters) when controlling the opening and closing of the upper layer IGBT 121 and the lower layer IGBT 122, and is capable of performing switching control of the PWM control parameters. The parameter switching means will be described later.

[0061] Figure 4 is a diagram that conceptually compares the time-dependent changes in the control in the low-speed start processing unit 172 and the time-dependent changes in the control in the high-speed start processing unit 171 until a certain target power consumption G is reached in the control means 13. Figures 4(A) to 4(E) show the control in the low-speed start processing unit 172, and Figures 4(F) to 4(H) show the control in the high-speed start processing unit. Furthermore, Figures 4(A) to 4(D), 4(F), and 4(G) show the changes in the duty cycle at a predetermined timing (for example, 50 times, 50 cycles) after one heater drive control (hereinafter referred to as "heater drive control") in the heater drive means 12 has been performed a predetermined number of times.

[0062] Here, "one heater drive control" refers to a series of controls that increase the duty cycle once (one step) to reach a target duty cycle Dm corresponding to the target power consumption G, execute PWM control (switching control), and output a certain power consumption. In other words, the period of heater drive control means the interval between the timing of the duty cycle increase.

[0063] In Figures (D) and (G), "G'" represents the overlap in the ON time of the upper IGBT121 and the lower IGBT122, and the sum of these areas represents the set target power consumption G (required value). The sum of the overlap area G' in Figure (D) is the height shown in Figure (E) (target power consumption G), and the sum of the overlap area G' in Figure (G) is the height shown in Figure (H) (target power consumption G). In Figure 4, IGBT1 represents the upper IGBT121, and IGBT2 represents the lower IGBT122.

[0064] As shown in Figures 4(A) to 4(D), 4(F), and 4(G), the power control means 17 of this embodiment controls the voltage applied to the gates of the upper IGBT 121 and lower IGBT 122, for example by PWM control, and changes the ratio of their open (on) / closed (off) states (duty cycle) over time, thereby controlling the energization state (amount of current flowing) to the resistive element 11. When the amount of current flowing to the resistive element 11 changes, the amount of heat generated by the resistive element 11 changes, and the power consumption changes.

[0065] Figures 4(A) to 4(D) show that in the low-speed start processing unit 172, the duty cycle gradually increases every 50 cycles from the start of processing (Figure 4(A)) (Figures 4(B) to 4(D)), and reaches the target duty cycle Dm after 200 cycles (50 cycles x 4) (Figure 4(D)).

[0066] Figures 4(F) and 4(G) show the state in the high-speed start processing unit 171 where, for example, the target duty cycle Dm is reached in 50 laps from the start of processing (Figure 4(F)) (Figure 4(G)).

[0067] In other words, the low-speed start processing unit 172 sets the increase in the duty cycle per cycle of heater drive control, that is, the average rate of increase in the duty cycle when considered on the time axis, to be smaller than that of the high-speed start processing unit 171. As a result, as shown in Figures (A) to (D), the low-speed start processing unit 172 controls the upper IGBT 121 and lower IGBT with PWM so that the duty cycle increases more gradually than that of the high-speed start processing unit 171, thereby controlling the conduction to the electrical resistance element 11. This reduces the average rate of increase in the power consumption of the electrical resistance element 11 (making it slower), and the time from the start of the power consumption increase (start of PWM control) to reaching the target duty cycle Dm corresponding to the requested value of the received power consumption request (overlap amount G', target power consumption G) becomes longer. Hereinafter, this control in the low-speed start processing unit 172 will be referred to as "low-speed start processing". In this case, the output (power consumption) of the electrical resistance element 11, as shown in Figure (E), rises at a certain angle (this angle represents the average rate of increase in power consumption) according to the change in duty cycle (amount of increase) from the start SS of the low-speed start process (after the PWM control start signal is turned on ("H")) until it reaches the target power consumption G.

[0068] In contrast, the high-speed start processing unit 171 sets the increase in the duty cycle per cycle of heater drive control, that is, the average rate of increase in the duty cycle when considered on the time axis, to be larger than that of the low-speed start processing unit 172. As a result, as shown in Figures (F) and (G), the high-speed start processing unit 171 controls the upper IGBT 121 and lower IGBT with PWM so that the duty cycle increases more significantly than that of the low-speed start processing unit 172, thereby controlling the conduction to the electrical resistance element 11. This increases the average rate of increase in the power consumption of the electrical resistance element 11 (making it faster), and assuming that the target duty cycle Dm corresponding to the requested value of the received power consumption request (target power consumption G set with overlap amount G') is the same as the target duty cycle Dm of the low-speed start processing unit 172, the time to reach this target from the start of the power consumption increase (start of PWM control) will be shorter than in the case of the low-speed start processing. Hereinafter, the control in this high-speed start processing unit 171 will be referred to as "high-speed start processing". In this case, as shown in Figure (H), the output of the electrical resistance element 11 rises from the start point FS of the high-speed start processing (after the PWM control start signal is turned on ("H")) at a steeper angle than the low-speed start processing unit 172 (this angle represents the average rate of increase in power consumption) in accordance with the amount of change (increase) of the duty cycle, until it reaches the target power consumption G.

[0069] More specifically, in the high-speed start processing unit 171, when the current supplied to the electrical resistance element 11 is increased (when the electrical resistance element 11 is switched from off to on, or when the required power consumption is increased), the time from the start of the increase in current supply to reaching the target power consumption G (hereinafter referred to as "time to reach target power consumption") is, for example, less than 5 seconds, preferably 2 seconds or less, and more preferably around 1 second or less.

[0070] Regardless of whether it is a high-speed start process or a low-speed start process, after reaching the target power consumption G, the control means 13 continues to control the voltage applied to the resistive element 11 using PWM control based on the power consumption requests received sequentially, thereby controlling the energization of the resistive element 11. In this way, the resistive element 11 consumes the required power through heat generation.

[0071] Furthermore, Figures 4(I) and 4(J) show an example of the change over time in the output (power) of the electrical resistance element 11 when the target power consumption G increases (increase 2) during a period in which output (increase 1) is being produced based on a certain power consumption request.

[0072] Figure 4(I) shows an example where, during a period in which a low-speed start process is performed and output is generated based on a certain power consumption request (first requested value (target power consumption G1)) from the start time SS of the process (start of power consumption increase), a power consumption request is received that includes a second requested value (target power consumption G2) which is larger than the first requested value, and a request for high-speed start processing (high-speed flag is, for example, on). In this case, the control means 13 executes high-speed start processing from the start time FS of the power consumption increase and outputs based on the second requested value (target power consumption G2). The amount of increase in the requested value at the start time FS of the high-speed start processing is the difference ΔG between the second requested value (target power consumption G2) and the first requested value (target power consumption G1).

[0073] Figure 4(J) shows an example where, during the period when high-speed start processing is performed and output based on a power consumption request (second requested value (target power consumption G2)) is being generated from the start time FS of the high-speed start processing (start of power consumption increase), a power consumption request is received that includes a first requested value (target power consumption G1) which is larger than the second requested value and a request for low-speed start processing (high-speed flag is off, for example). In this case, the control means 13 executes low-speed start processing from the start time SS of the power consumption increase and outputs based on the first requested value (target power consumption G1). The amount of increase in the requested value at the start time SS of the low-speed start processing is the difference ΔG between the first requested value (target power consumption G1) and the aforementioned second requested value (target power consumption G2).

[0074] The "average rate of increase of the duty cycle" described here is "the average rate of increase of the duty cycle during the period from the start of the increase in power consumption (start of PWM control) until the target duty cycle Dm corresponding to the set target power consumption G is reached and the increase in the duty cycle ends."

[0075] In other words, in heater drive control, the duty cycle is gradually increased at predetermined cycles (one or more cycles) until it reaches the target duty cycle Dm. Various methods can be applied to the amount of increase in the duty cycle in a predetermined cycle of heater drive control (the manipulated amount to increase the duty cycle), such as a method in which a certain predetermined amount (fixed value) is gradually increased at each of the one or more cycles of heater drive control, or a method in which the manipulated amount is calculated at each of the one or more cycles of heater drive control. In this embodiment, as an example, at each predetermined reference time (for example, one cycle of heater drive control), the amount of increase in the duty cycle to be increased in that cycle (manipulated amount) is calculated. Hereinafter, this amount of increase in the duty cycle (the manipulated amount for switching the upper IGBT 121 and the lower IGBT 122) will be referred to as the "duty operated amount". In a certain cycle of heater drive control, the duty operated amount for that cycle is added to the current (previous) duty cycle to determine the duty cycle for that cycle, and power corresponding to the duty cycle is output. Details of the duty cycle will be described later.

[0076] <Heater control processing> Referring to Figures 5 and 6, an example of the electrical resistance element 11 (heater) control process performed by the control means 13 of the heating device 10 will be described. Figure 5 is a flowchart showing an example of the heater control process flow, and Figure 6 is a flowchart showing an example of the heater drive control process flow.

[0077] During operation, the heating device 10 repeatedly executes the heater control process (steps S01 to S13) shown in Figure 5. This heater control process is executed at a predetermined interval (specifically, for example, approximately 2 msec interval) (for example, by being called from the main program that oversees the operation of the heating device 10).

[0078] First, in step S01, the forced shutdown means 20 determines, for example, whether or not an abnormality has been detected (whether or not the forced shutdown condition has been met). Specifically, for example, it determines whether (1) there is a detection by the protection / fault sensor and (2) the fault detection of the overvoltage sensor is incomplete. If there is a detection by the protection / fault sensor (Yes), the forced shutdown means 20 proceeds to step S13. The forced shutdown means 20 also proceeds to step S13 if the fault detection of the overvoltage sensor is incomplete (Yes). On the other hand, if there is no detection by the protection / fault sensor and the fault detection of the overvoltage sensor is complete (No), the forced shutdown means 20 proceeds to step S03.

[0079] In step S03, the request acquisition means 14 acquires power consumption requests. That is, power consumption requests are acquired at the cycle of the heater control process (for example, a cycle of approximately 2 msec). Each power consumption request includes a request value. The request value is a value (information) corresponding to the target power consumption G, and even if there is no actual power consumption request, it includes information indicating that there is no consumption request (for example, "0" or a value less than the minimum request threshold).

[0080] Furthermore, predetermined initialization processes are performed, such as clearing the values ​​of a judgment timer (part of the various sensors) and other sensors used to determine whether or not the heater drive control described later can be executed.

[0081] Steps S01 and S03 may be executed almost simultaneously, or the order of steps S01 and S03 may be reversed.

[0082] In step S05, the request determination means 15 determines whether power consumption requests have been successfully acquired and whether there are any actual power consumption requests based on these. The request determination means 15 compares the requested value with a preset minimum requested threshold (for example, 200W). If the requested value is less than the minimum requested threshold, it determines that there are "no power consumption requests" and considers the requested value to be "0". If the requested value is equal to or greater than the minimum requested threshold, it determines that there are actual "power consumption requests" from the air conditioning ECU 1 or charging ECU 2.

[0083] If step S05 determines that there is a power consumption request, proceed to step S07; otherwise, proceed to step S13.

[0084] In step S07, for example, the request determination means 15 sets the requested value (the maximum requested value if multiple power consumption requests are acquired simultaneously) as the target power consumption G. Specifically, the requested value is set as the target power consumption parameter for PWM control.

[0085] In step S09, it is determined whether or not to execute the heater drive control in step S11. Specifically, for example, it is determined whether or not a period based on the carrier frequency of PWM control (the frequency that determines the pulse width modulation period) has elapsed. That is, the value of the determination timer (sensor) that determines whether or not to execute the heater drive control is obtained, and the value of the determination timer is compared with a predetermined determination period (for example, a predetermined period such as approximately 18 ms) that is set in advance based on the carrier frequency (for example, 57 Hz). If the value of the determination timer is shorter than the determination period (No), the process proceeds to step S13, and the value of the determination timer (sensor) is updated. Specifically, the time of one cycle of the heater control process (approximately 2 msec) is incremented.

[0086] In step S09, if the acquired value of the judgment timer exceeds the judgment period (Yes), the heater drive control process (see Figure 6) is executed in step S11. The process also proceeds to step S13 in parallel with the heater drive control process. In step S13, the value of the judgment timer (sensor) is cleared, and if there are other sensor values ​​(for example, outputs from the heater drive control process (such as power consumption values)), the sensor value is updated. In this embodiment, one control cycle of the heater drive control process is, for example, a period based on the carrier frequency (for example, about 18 msec), which is longer than one cycle of the heater control process (about 2 msec). Even while the heater drive control process is being executed, the heater control process does not wait for its output, and steps S01 to S13 (such as acquiring power consumption requests and incrementing the judgment timer) are repeatedly executed at predetermined intervals (about 2 msec).

[0087] <Heater drive control processing> The heater drive control process will be explained with reference to Figure 6. In step S09 of the heater control process (Figure 5), if the acquired value of the determination timer exceeds the determination period (Yes), the heater drive control process is executed. One cycle of the heater drive control process is the period from step S111 to step S125 shown in Figure 6, and specifically, for example, is a period based on the carrier frequency (for example, about 18 msec).

[0088] In step S111, the start processing determination means 16 determines, based on predetermined determination conditions, whether to process the acquired power consumption request using the high-speed start processing unit 171 or the low-speed start processing unit 172.

[0089] If the high-speed flag of the power consumption request received by the request determination means 15 is "on" (Yes), it is determined that the high-speed start processing unit 171 will process the request, and the process proceeds to step S113. If the high-speed flag of the power consumption request received by the request determination means 15 is "off" (No), it is determined that the low-speed start processing unit 172 will process the request, and the process proceeds to step S121.

[0090] In step S113, the high-speed start processing unit 171 performs parameter switching control to determine the calculation parameters for the duty cycle. The calculation parameters for the duty cycle are part of the PWM control parameters.

[0091] In this embodiment, the calculation parameters for the duty cycle include, for example, at least three types of parameters: a high-speed high-voltage parameter for high-speed start processing, a high-speed low-voltage parameter for high-speed start processing, and a low-speed parameter for low-speed start processing.

[0092] The high-speed high-voltage parameter is a parameter for calculating the duty cycle amount, which is set when the voltage applied to the electrical resistance element 11 during the high-speed start process is a high voltage exceeding the threshold voltage. In this case, the threshold voltage is set to any voltage in the range of 200V to 600V, preferably any voltage in the range of 250V to 500V.

[0093] The high-speed low-voltage parameter is a parameter used to calculate the duty cycle amount, which is set during the high-speed start process when the applied voltage to the electrical resistance element 11 is a low voltage below the threshold voltage. Hereinafter, both the high-speed high-voltage parameter and the high-speed low-voltage parameter are parameters used in the high-speed start process, and will therefore be simply referred to as the high-voltage parameter and the low-voltage parameter.

[0094] The low-speed parameter is a parameter used to calculate the duty cycle amount, which is set when performing a low-speed start process.

[0095] In other words, in step S113, the applied voltage to the electrical resistance element 11 at that time (the voltage of the high-voltage power supply 131 shown in Figure 2) is acquired. If the applied voltage exceeds the threshold voltage (Yes), a high-voltage parameter is set as the calculation parameter for the duty cycle (step S115). If the applied voltage to the electrical resistance element 11 is below the threshold voltage (No), a low-voltage parameter is set as the calculation parameter for the duty cycle (step S117). This control is called parameter switching control.

[0096] In step S119, following step S115 or step S117, the duty cycle to be set in the current control cycle of the heater drive control is determined (calculated). Hereinafter, one cycle of the heater drive control will be referred to as the "heater drive control cycle". The duty cycle in the current heater drive control cycle is determined by adding the increase in the duty cycle (duty operation amount) to be increased from the previous heater drive control cycle in order to increase power consumption, to the duty cycle set (executed) in the previous heater drive control cycle.

[0097] The duty cycle amount used is the value calculated in the previous heater drive control cycle (for the next cycle).

[0098] In other words, in step S119, the duty cycle set for the current (this) heater drive control cycle and the duty cycle amount to be used for the next heater drive control cycle are calculated and determined.

[0099] The duty cycle used in the next heater drive control cycle is specifically calculated based on the difference between the target power consumption set in the current (this) heater drive control cycle and the power consumption in the current (this) heater drive control cycle (hereinafter, this difference is referred to as the "power difference"). The calculated duty cycle is updated as various sensor values ​​in the sensor value update process (step S13) of the heater control process (Figure 5), and is acquired and referenced in the next heater drive control cycle.

[0100] The target power consumption set for the current heater drive control cycle is the value of the target power consumption G set during the execution of step S119. Furthermore, the power consumption for the current heater drive control cycle is the amount of energy (heat generated) of the electrical resistance element 11 that is output (actually output or planned to be output) during the current heater drive control cycle. The electrical resistance element 11 consumes power according to a set duty cycle during one PWM control cycle. In other words, the power consumed during the current heater drive control cycle is the power actually consumed according to the set duty cycle, or the power planned to be consumed during the current heater drive control cycle according to the set duty cycle.

[0101] In this embodiment, feedback control is performed to calculate the duty cycle amount for the next heater drive control cycle according to the power difference in the current heater drive control cycle (the difference between the target power consumption G and the actual power consumption) for each heater drive control cycle (approximately every 18ms cycle). Specifically, this feedback control is, for example, PI control, and the duty cycle amount for the next cycle is calculated by applying proportional gain and integral gain to the power difference (correcting the power difference with PI control). In other words, the calculation parameters for the duty cycle amount in this embodiment (the high-voltage parameter set in step S115 and the low-voltage parameter set in step S117) are all set by (including) a value based on the proportional gain in PI control (hereinafter referred to as the "P value") and a value based on the integral gain (hereinafter referred to as the "I value"). As a specific method for setting the high-voltage parameter and the low-voltage parameter, for example, the P value is first set appropriately so that a desired value is obtained (approached). In this embodiment, as an example, the P value of the high-voltage parameter is set to a value larger than the P value of the low-voltage parameter. The I value of the high-voltage parameter is set to an appropriate value according to the P value of the high-voltage parameter, and the I value of the low-voltage parameter is set to an appropriate value according to the P value of the low-voltage parameter.

[0102] Furthermore, an upper limit (operational amount upper limit) is set for the duty cycle operation amount. That is, in step S119, if the duty cycle operation amount calculated using the high-voltage parameter or the low-voltage parameter exceeds the operational amount upper limit in the high-speed start process, the operational amount upper limit is set to the duty cycle operation amount calculated for that period. For example, the upper limit of the duty cycle operation amount in the high-speed start processing unit 171 is, for example, 20%.

[0103] Then, in step S125, PWM control is performed according to the duty cycle set in step S119. In step 125, the power control means 17 (high-speed start processing unit 171) starts PWM control of the voltage applied to the electrical resistance element 11 based on the set PWM control parameters (high voltage parameters), triggered by the ON ("H") of the PWM control start signal, and controls the supply of power to the electrical resistance element 11. In this way, the amount of duty cycle operation (for the next cycle) is calculated according to the power difference for each heater drive control cycle, and the amount of increase in power consumption is adjusted for each heater drive control cycle.

[0104] Consequently, the duty cycle increases with each heater drive control cycle, and the electrical resistance element 11 consumes the power required by the heat generated, ultimately reaching the target power consumption G at high speed.

[0105] If it is determined in step S111 that processing should be performed in the low-speed start processing unit 172, then in step S121, the low-speed start processing unit 172 sets the low-speed parameter as a parameter for calculating the duty cycle. The low-speed parameter is, for example, one type of parameter, but like the high-speed high-voltage parameter and the high-speed low-voltage parameter, it is a value that is set based on (including) the P value and I value in PI control (the values ​​are different).

[0106] Step S123 performs the same processing as step S119. That is, it calculates the duty cycle amount for the next control cycle of the heater drive control according to the difference (power difference) between the target power consumption set in the current heater drive control cycle and the power consumption in the current heater drive control cycle, and also calculates (determines) the duty cycle ratio for the current heater drive control cycle.

[0107] In addition, an upper limit (operation limit) is set for the duty cycle amount even in the low-speed start process. That is, in step S123, if the duty cycle amount calculated by the low-speed parameter exceeds the operation limit in the low-speed start process, the operation limit is set to the duty cycle amount calculated for that period. As an example, the upper limit of the duty cycle amount in the low-speed start processing unit 172 is, for example, 0.2%, preferably 0.15% (preferably 0.12%, etc.).

[0108] Then, in step S125, PWM control is performed according to the duty cycle set in step S123. In step 125, the power control means 17 (low-speed start processing unit 172) starts PWM control of the voltage applied to the resistive element 11 based on the set PWM control parameters (low-speed parameters), triggered by the PWM control start signal being turned ON ("H"), and controls the supply of power to the resistive element 11. In this way, with each heater drive control cycle, the duty cycle increases according to the power difference, the resistive element 11 consumes the power required by the heat generated, and finally reaches the target power consumption G at a slower speed than the high-speed start processing unit 171.

[0109] The output power (power consumption) and the calculated duty cycle are updated as various sensor values ​​in the sensor value update process (step S13) of the heater control process (Figure 5), and are referenced in the next heater drive control cycle.

[0110] In the heater drive control process, the duty cycle amount for the next control cycle is calculated in one cycle of PWM control (pulse width modulation cycle, for example, approximately 18 msec). In other words, one PWM control is executed every 8 cycles of the higher-level heater control process, and the duty cycle amount and duty cycle ratio are calculated for each heater drive control cycle.

[0111] <Method for calculating duty cycle and duty cycle operation amount> Referring to Figure 7, the method for calculating the duty cycle and duty cycle amount for each heater drive control cycle will be explained in detail. This figure is a conceptual diagram illustrating an example of a method for calculating the duty cycle and duty cycle amount.

[0112] In Figure 7, each period of the heater drive control cycle is shown in the columns, and the processing in each period is shown in the rows. The first column ((1)~(4)) represents the processing of the first cycle after the start of the heater drive control process (increasing the heater output (including from off to on)), the second column ((5)~(10)) represents the processing of the (n-1)th cycle after the start of the heater drive control process, the third column ((11)~(14)) represents the processing of the nth cycle after the start of the heater drive control process, and the fourth column ((15)~(18)) represents the processing of the (n+1)th cycle after the start of the heater drive control process. In the following explanation of Figure 7, the heater drive control cycle may be simply referred to as the "period".

[0113] Furthermore, the first line ((1), (5), (11), (15)) is a step to calculate the duty cycle [%] of the current heater drive control cycle, the second line ((2), (6), (12), (16)) is a step to obtain the heater output (power consumption Q [W]) when operated with the duty cycle of the current cycle, the third line ((3), (7), (13), (17)) is a step to calculate the difference (power difference Y [W]) between the target power consumption G in the current cycle and the power consumption Q in the current cycle, and the fourth line ((4), (8), (14), (18)) is a step to calculate the duty cycle operation amount [%] for the next cycle.

[0114] Here, "duty cycle for each heater drive control cycle" refers to the ratio of the duty cycle for each heater drive control cycle, where the target duty cycle for outputting the maximum value of the target power consumption G (e.g., 10 kW) is 100%. Also, "target duty cycle for outputting the target power consumption G" refers to the case where the overlap of the ON states of the upper IGBT 121 and the lower IGBT 122 is, for example, 94% to 96%.

[0115] First, in the first cycle after the start of the heater drive control process, the duty cycle (Duty ratio 1) for that cycle (this time) is equal to the duty cycle operation amount (Duty operation amount 1) for that cycle, and this is set to, for example, the upper limit value (for example, 20%) in the high-speed start processing unit 171 (1).

[0116] Then, the power consumption Q1 for the current period is obtained as a result of operating the upper IGBT121 and lower IGBT122 so that the duty cycle is 1 (20%) (2), and the power difference Y1 for the current period is calculated (3). The power difference Y1 is the difference between the target power consumption G and the current power consumption Q1.

[0117] Then, the duty cycle amount (Duty cycle amount 2) for the next cycle (2nd cycle) is calculated (4). At this time, the duty cycle amount for the next cycle is the change from the duty cycle ratio in the current cycle, and is calculated by correcting the power difference Y (Y1) of the current cycle using PI control. The proportional gain (P value) and integral gain (I value) in this PI control are values ​​set as either high-voltage parameters, low-voltage parameters, or low-speed parameters.

[0118] In other words, for example, the duty cycle variable 2 is calculated as a function of the power difference Y1, with P and I as parameters, by the following equation (Equation 1). Duty operation amount 2=Y1(P,I) (Formula 1)

[0119] The duty cycle for the second period is the sum of the duty cycle for the first period (Duty ratio 1) and the duty cycle control variable 2.

[0120] This process is repeated. In the (n - 1)-th cycle after the start of the heater drive control process, the duty ratio of the current cycle is n-1 ), and the duty ratio of the previous cycle n-2 ), and the duty operation amount n-1 (the duty operation amount based on the previous power difference Y n-2 ) are used to calculate the following (Equation 2) (5). Duty ratio n-1 = Duty ratio n-2 + Duty operation amount n-1 (Equation 2)

[0121] Then, the power consumption Q n-1 of the current cycle as a result of operating the upper IGBT 121 and the lower IGBT 122 so that the duty ratio n-1 is obtained (6), and the power difference Y n-1 of the current cycle is calculated (6). The power difference Y n-1 is the difference between the target power consumption G and the current power consumption Q n-1 .

[0122] Then, the power difference Y n-1 is corrected by PI control, and the duty operation amount (Duty operation amount n ) for the next cycle (n-th cycle) is calculated in the same manner as (Equation 1) (8). The duty operation amount n is calculated by the following (Equation 3) as a function of the power difference Y n-1 with P value and I value as parameters. Duty operation amount n = Y n-1 (P, I) (Equation 3)

[0123] In addition, when calculating the duty operation amount n , in addition to the power difference Y n-1 of the current cycle, the power difference Y n-2 of the previous cycle may be used. Specifically, the power difference Y n-2 of the previous cycle is calculated by the following (Equation 4) (9). Previous power difference Yn-2 = Previous target power G - Previous power consumption Q n-2 (Formula 4)

[0124] And, Duty cycle n Replacing (Equation 3), we have the power difference Y, with P and I values ​​as parameters. n-1 And the previous power difference Y with the P value as a parameter. n-2 As a function of (10), it is calculated by the following (Equation 5). Duty operation amount n =Y n-1 (P,I)+Y n-2 (P) (Formula 5)

[0125] In this case, the duty cycle calculation steps in (14) and (18) shown in Figure 7 are also performed using (Equation 5) in the same way as in (10) in Figure 7, but this will be omitted in the following explanation.

[0126] For example, if the noise effect is significant, or if there is a large discrepancy between the target power consumption G and the power consumption Q, the power difference (Y) from the previous cycle may be used. n-2 It is desirable to calculate the duty cycle amount for the next period by (Equation 5), also referring to (Equation 5). Also, the power difference Y in the period before the previous period is calculated. n-3 (For example) You may also refer to multiple past power differences.

[0127] In the nth cycle after the start of the heater drive control process, the duty cycle for that cycle (this time) is determined. n ) is the duty cycle of the previous period (Duty ratio) n-1 ) and the duty cycle amount calculated by (Equation 3) in the previous period. n (Previous power difference Y) n-1 The duty cycle (based on) and are used to calculate the following (Equation 6) (11). Duty ratio n =Duty ratio n-1 +Duty operation amount n (Formula 6)

[0128] And the duty cycle nThe power consumption Q for this period (this time) is the result of manipulating the upper IGBT121 and lower IGBT122 in such a way. n (12) obtain the power difference Y for the current period. n Calculate (13). Power difference Y n This is the target power consumption G and the current power consumption Q. n This is the difference.

[0129] Then, the power difference Yn is corrected by PI control, and the duty cycle amount (Duty control amount) for the next cycle (n+1th cycle) is adjusted. n+1 ) is calculated in the same manner as (Equation 1) (14). Duty operation n The power difference Y is a parameter of the P value and I value. n It is calculated as a function of (Equation 7) below. Duty operation amount n+1 =Y n (P,I) (Formula 7)

[0130] Similarly, in the n+1th period after the start of the heater drive control process, the duty cycle for that period (this time) is calculated. n+1 ) is the duty cycle of the previous period (Duty ratio) n ) and the duty cycle amount calculated by (Equation 7) in the previous period. n+1 (Previous power difference Y) n The duty cycle (based on) and are used to calculate the following (Equation 8) (15). Duty ratio n+1 =Duty ratio n +Duty operation amount n+1 (Formula 8)

[0131] And the duty cycle n+1 The power consumption Q for this period (this time) is the result of manipulating the upper IGBT121 and lower IGBT122 in such a way. n+1 (16) obtain the power difference Y for the current period. n+1 Calculate (17). Power difference Y n+1 This is the target power consumption G and the current power consumption Q. n+1 This is the difference.

[0132] And the power difference Y n+1 This is corrected by PI control, and the duty cycle amount (Duty control amount) in the next cycle (n+2th cycle) is corrected. n+2 ) is calculated in the same manner as (Equation 1) (18). Duty operation n+2 The power difference Y is a parameter of the P value and I value. n+1 It is calculated as a function of (Equation 9) below. Duty operation amount n+2 =Y n+1 (P,I) (Formula 9)

[0133] These processes are repeated until the target power consumption G is reached. Note that in the explanation of Figure 7, the target power consumption G is shown for each cycle, but the value of the target power consumption G is not necessarily constant in each cycle and may fluctuate.

[0134] Figure 8 is a graph showing the relationship between the applied voltage to the electrical resistance element 11 and the time it takes to reach the target power consumption G, particularly in the high-speed start processing unit 171. Figure 8(A) is a graph showing the relationship between the applied voltage and the time to reach the target power consumption when the entire applied voltage range (120V to 820V) is controlled using high-voltage parameters and low-voltage parameters, respectively. Figure 8(B) is a graph showing the relationship between the applied voltage and the time to reach the target power consumption when the parameter switching control of this embodiment is performed for a certain range of applied voltage (120V to 820V). In both graphs, the horizontal axis represents the applied voltage to the electrical resistance element 11, and the vertical axis represents the time to reach the target power consumption.

[0135] In Figure 8(A), the solid line represents the result of controlling the applied voltage across the entire range (120V to 820V) using high-voltage parameters, while the dashed line represents the result of controlling the applied voltage across the entire range (120V to 420V) using low-voltage parameters. Note that with the low-voltage parameters, convergence does not occur in the voltage range above 420V, making measurement impossible.

[0136] Thus, if the entire range of applied voltage is controlled by high-voltage parameters, the time to reach the target power consumption becomes long, ranging from 1000 msec to 8000 msec, when the applied voltage is, for example, 400 V or less, and the variation in this time becomes large.

[0137] Furthermore, if the entire range of applied voltage is controlled using low-voltage parameters, convergence will cease when the applied voltage exceeds, for example, 400V.

[0138] In the parameter switching control of this embodiment, the threshold voltage is set to a voltage within the range of, for example, 200V to 500V. If the applied voltage is lower than the threshold voltage, the low-voltage parameter is used, and if the applied voltage exceeds the threshold voltage, the high-voltage parameter is set as the PWM control parameter (duty cycle calculation parameter). As a result, as shown in Figure 8(B), the time to reach the target power consumption in the case of high-speed start processing can be kept to approximately 1 sec across almost the entire range of fluctuating applied voltage (for example, 200V to 800V). Furthermore, even when the applied voltage is 120V, for example, the time to reach the target power consumption can be reduced to approximately 2200 msec, thus suppressing variations in the time to reach the target power consumption across the entire range of applied voltage.

[0139] Furthermore, for high-voltage and low-voltage parameters, the P value (and corresponding I value) is appropriately selected so that the time to reach the target power consumption in the case of high-speed start processing is approximately 1 second across the entire range of fluctuating applied voltages.

[0140] In this embodiment, for each heater drive control cycle, the difference between the target power consumption and the power consumption in that cycle (power difference) is calculated, and the duty cycle amount for the next heater drive control cycle is calculated by correcting this power difference using PI control. In this way, the target power consumption G can be reached efficiently. Furthermore, since the number of duty cycle operations required to reach the target power consumption G is reduced, the high-speed start processing unit 171 in particular can reach the target power consumption G earlier.

[0141] Furthermore, the parameters used to calculate the duty cycle (PWM control parameters) are set to values ​​based on the proportional gain (and integral gain) in PI control. At least in the high-speed start processing unit 171, parameter switching control is performed to switch between low-voltage parameters and high-voltage parameters according to the voltage applied to the electrical resistance element 11, and to calculate the duty cycle for each predetermined control period (heater drive control period).

[0142] As a result, even when the applied voltage to the electrical resistance element 11 spans a wide bandwidth, the time to reach the target power consumption in the case of high-speed start processing can be kept to, for example, less than 5 seconds (preferably within 2 seconds, more preferably around 1 second) across the entire bandwidth, and variations in the time to reach the target power consumption can be suppressed.

[0143] Although not shown in the diagrams and detailed explanations, the low-speed start processing unit 172 may also perform parameter switching control to switch between low-speed high-voltage parameters and low-speed low-voltage parameters.

[0144] The above describes an example of the heating device 10 of this embodiment. The request acquisition means 14, request determination means 15, start processing determination means 16, and power control means 17 described in Figure 3 are just examples, and any configuration that can at least realize the request acquisition function, request determination function, start processing determination function, and power control function of the heating device 10 described above is acceptable. For example, multiple means among these (e.g., request acquisition means 14 and request determination means 15, or start processing determination means 16 and power control means 17) may be composed of a single means, or a single means (e.g., start processing determination means 16 or power control means 17) may be divided into multiple means.

[0145] Furthermore, some or all of these hardware components may be composed of software, or vice versa. Also, these components are not limited to those implemented on a single control board, but may be composed of electronic components on multiple control boards.

[0146] Furthermore, while the example given illustrates that the voltage control in the power control means 17 is PWM control, it is not limited to this. For example, a PFM (Pulse Frequency Modulation) method may be used, in which the on (or off) time of the pulse is kept constant and the off time (or on time) is varied for control.

[0147] Furthermore, in the above embodiment, the source of the power consumption request was exemplified as the air conditioning ECU1 and charging ECU2, which are external devices of the heating device 10. However, the source of the surplus power consumption request and / or the air conditioning power consumption request may be means included in the heating device 10.

[0148] For example, the heating device 10 may be configured to acquire information from an external vehicle air conditioning system, generate an air conditioning power consumption request in a request transmission means inside the heating device 10, and transmit it to the request acquisition means 14 of the heating device 10. Similarly, the heating device 10 may be configured to acquire information from an external vehicle control unit, generate a surplus power consumption request in a request transmission means inside the heating device 10, and transmit it to the request acquisition means 14 of the heating device 10.

[0149] Furthermore, the source of the first power consumption request is not limited to the control unit (air conditioning ECU1) of the vehicle's air conditioning system, but may be the control unit (ECU) of another device, and the source of the second power consumption request is not limited to the vehicle control unit (charging ECU2), but may be the control unit (ECU) of another device.

[0150] Furthermore, the upper switching element 121 and the lower switching element 122 are not limited to IGBTs, but may be other voltage-driven transistors. For example, they may be field-effect transistors, and specifically, enhancement-type n-channel insulated-gate field-effect transistors (e.g., MOSFETs: metal-oxide-semiconductor field-effect transistors).

[0151] Furthermore, the voltage control in the power control means 17 may, for example, appropriately select and set both PWM control and PFM control when the heating device 10 is put into use, or it may be possible to switch between the two (select each time) while the heating device 10 is operating. Other types of voltage control may also be used.

[0152] It should be noted that the heating device of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present invention. [Industrial applicability]

[0153] The heating device 10 of the present invention can be used in the field of auxiliary equipment for vehicles. [Explanation of symbols]

[0154] 1. Control board 2 cases 2A Upper case 2B Lower case 3 pipes 3A inlet 3B Outlet 4th Regeneration Equipment 5 Power supply section 5A power supply terminal 6. Energy storage device 10 Heating device 11 Electrical resistance element 12 Heater driving means (heater driving circuit) 13 Control means (control unit) 14 Request acquisition means 15 Request determination means 16 Start processing determination means 17 Power control means 19. Means of communication 20 Forced shutdown means 21. Vehicle air conditioning system 121 Upper layer switching element 122 Lower layer switching element 123 Upper-level driver 124 Lower-level drivers 125 Upper layer capacitor 126 Lower layer capacitor 130 Driver Power Supply 131 High-voltage power supply 171 High-speed start processing unit 172 Low-speed start processing unit Dm Target duty cycle

Claims

1. An electrical resistance element capable of generating heat in response to power consumption requests from a vehicle, Control means capable of controlling the power consumption by the electrical resistance element, A heating device comprising an upper switching element and a lower switching element connected in series via the aforementioned electrical resistance element, The control means is The upper switching element and the lower switching element can be controlled to open and close. The amount of increase in power consumption over a predetermined reference time can be adjusted according to the voltage applied to the electrical resistance element. The predetermined reference time is a predetermined control period that includes at least the opening and closing control, At each predetermined control cycle, the amount of operation for the opening and closing control in the next control cycle is calculated according to the difference between the target power consumption in the current control cycle and the power consumption of the electrical resistance element, and the amount of increase is adjusted. Parameter switching control can be performed to calculate the amount of the switching control operation for each predetermined control cycle by switching between a low-voltage parameter when the applied voltage is lower than the threshold voltage and a high-voltage parameter when the applied voltage is higher than the threshold voltage, according to the applied voltage. A heating device characterized by the following features.

2. The predetermined reference time is a predetermined control period by the control means. The heating apparatus according to feature 1.

3. The control means is In the switching control described above, a high-speed start processing unit controls the upper switching element and the lower switching element to reach the target power consumption relatively quickly, The switching control includes a low-speed start processing unit that controls the upper and lower switching elements to reach the target power consumption at a lower speed than the high-speed start processing unit, At least in the high-speed start processing unit, the parameter switching control is capable of being executed. The heating apparatus according to feature 1.

4. The control means is configured to control the conduction to the electrical resistance element using PWM control. The control means is A high-speed start processing unit that performs control to reach a target duty cycle corresponding to the aforementioned power consumption request in a short time, The system includes a low-speed start processing unit that performs control to reach a target duty cycle corresponding to the power consumption request in a longer time than the high-speed start processing unit, At least in the high-speed start processing unit, the parameter switching control can be executed, The high-voltage parameter and the low-voltage parameter are values ​​based on the proportional gain and integral gain in PI control. The heating apparatus according to feature 1.

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