JP4244880B2 - Generator protection device and generator protection method - Google Patents

Description

  The present invention relates to a generator protection device and a generator protection method for preventing, for example, a thermal load of a generator mounted on a vehicle from becoming excessive.

  Conventionally, a technique for suppressing a state in which the electrical energy of a generator is lost due to a thermal load is known from Patent Document 1 below.

The generator protection device described in Patent Document 1 does not use a thermistor that directly measures the temperature of the generator or a flow rate sensor that measures the coolant flow rate of the liquid-cooled generator, and does not use the thermal sensor of the generator. The load status is being judged. That is, this generator protection device obtains the actual output current reduction amount with respect to the reference output current obtained by detecting the generator speed and the generator field current. And it determines with the thermal load of a generator becoming large, so that this fall amount becomes large.
JP 2003-87966 A

  By the way, in the technique described in Patent Document 1 described above, since the thermal load state is determined based on the actual output current of the generator, the heat including the rotor coil, stator coil, and diode, which are the components of the generator. That is, it was determined the state of the dynamic load. However, since each component of the generator has a different value for determining that it is in a thermal overload state, the conventional technology cannot be said to optimally determine the generator overload. was there.

  Therefore, the present invention has been proposed in view of the above-described situation, and it is possible to optimally determine the overload of the generator and reliably protect the generator. It aims to provide a protection method.

  The present invention is detected by a rotation speed detection means for detecting the rotation speed of a generator, a current detection means for detecting a power generation current of the generator, a voltage detection means for detecting a power generation voltage of the generator, and a voltage detection means. Generator atmospheric temperature calculating means for calculating the generator ambient temperature based on the generated voltage of the generator, and the storage means detects the rotational speed of the generator detected by the rotational speed detecting means and the current detecting means. A temperature characteristic map indicating changes in the component temperature of the generator with respect to changes in the generator current and the change in the generator atmosphere temperature calculated by the generator atmosphere temperature calculation means is created and stored in advance.

  Then, the present invention provides a generator rotation speed detected by the rotation speed detection means, a generator current detected by the current detection means, and a generator ambient temperature calculation means by the estimation means during operation of the generator. Based on the generator ambient temperature calculated by the above, reference is made to the temperature characteristic map stored in the storage means, the component temperature of the generator is estimated, and based on the component temperature of the generator estimated by the estimation means Thus, the above-described problem is solved by controlling the operation of the generator by the control means.

  According to the generator protection device and the generator protection method according to the present invention, the change in the component temperature with respect to the change in the generator ambient temperature based on the power generation voltage of the generator, the number of revolutions of the generator, and the generation current of the generator A temperature characteristic map is stored, and the component temperature is estimated by referring to the temperature characteristic map based on the actually detected generator ambient temperature, generator speed, and generator power generation current. Since it controls the operation of the generator, it is not necessary to provide a sensor for detecting the temperature in the generator, and the optimum generator overload can be determined in consideration of the component temperature for each component of the generator. The machine can be reliably protected.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

  In the vehicle electrical system as shown in FIG. 1, the present invention is a generator protection device that determines the thermal load of the generator 10 mounted on the vehicle and protects the generator 10 from an excessive thermal load. This is applied to the control unit 12.

[Configuration of vehicle electrical system]
As shown in FIG. 1, the vehicle electrical system controls the operation of a generator 10 that is an alternator (alternator), an engine 11 that is an internal combustion engine that drives the generator 10, and an electrical load 14. An ECU (Electric Control Unit) 13 is connected. This vehicle electrical system drives the generator 10 under the control of the control unit 12, accumulates the electric power generated by the generator 10 in a battery (not shown), and controls the electric loads 14 </ b> A and 14 </ b> B (hereinafter collectively referred to as the ECU 13). Simply called “electric load 14”).

  The engine 11 is connected to the generator 10 via a pulley and a belt (not shown), and drives the generator 10. An engine speed of the engine 11, that is, a speed signal for obtaining the speed of the generator 10 is supplied to the control unit 12.

  The generator 10 operates by the driving force of the engine 11 and generates AC power. The generator 10 is configured by integrating a regulator formed of an IC and semiconductor elements such as a power transistor and a diode, and converts the output current value to a constant value by the regulator to charge the battery.

  The ECU 13 includes a relay circuit 13A for the electric load 14A and a relay circuit 13B for the electric load 14B. When operating the electrical load 14, the ECU 13 supplies power to the electrical load 14 by receiving power from the battery and turning on the relay circuit. Further, according to the control of the control unit 12, the ECU 13 energizes the electric loads 14A and 14B that are necessary for traveling while blocking and restricting the electric loads that are not necessary for traveling. Do.

  The control unit 12 stores a program for performing processing for controlling the operation of the generator 10, processing for protecting the generator 10 (generator protection processing), processing for controlling the ECU 13, a temperature characteristic map described later, and the like. The microcomputer includes a ROM (Read Only Memory), a RAM (Random Access Memory), and a CPU (Central Processing Unit) that executes a program stored in the ROM. The control unit 12 normally gives a power generation voltage command to the generator 10 and adjusts the operating duty ratio of the power transistor constituting the power generator 10 to supply power to the battery with a power generation voltage corresponding to the power generation command value. .

  Further, the control unit 12 detects the generated voltage and generated current of the generator 10 and the rotation speed of the engine 11 when the generator 10 is generating power, and configures the generator 10 ambient temperature and the generator 10. The temperature of each part (component) to be estimated is estimated. Then, the control unit 12 controls the power generation voltage of the generator 10 to be lowered according to the temperature of each component, the control to stop the operation of the electric load 14, the power generation stop and power generation start control of the power generator 10, etc. Perform generator protection.

  In the vehicle electrical system shown in FIG. 1, the control unit 12 and the ECU 13 may not be provided separately but may be integrated as necessary.

[Generator protection treatment]
Next, in the vehicle electrical system as described above, the processing procedure of the generator protection processing by the control unit 12 will be described with reference to the flowchart of FIG.

  First, the control part 12 performs the pre-process which estimates the component temperature of the generator 10 by performing the process of step S1-step S4.

  Specifically, in step S1, the control unit 12 detects the power generation voltage Valt (ALT: alternator) of the generator 10, and compares the power generation voltage Valt with a preset voltage Vs set in advance. Here, the power generation voltage Valt varies depending on the temperature characteristics of the elements provided inside the regulator of the generator 10. Further, the set voltage Vs is a high temperature for the generator 10 such that the thermal load of the components of the generator 10 may be excessive, and the generated voltage Valt of the generator 10 is thermally excessive. A temperature that decreases with the load is obtained in advance by an experiment using the generator 10 or the like.

  Then, when the generated voltage Valt is lower than the set voltage Vs, the control unit 12 does not apply an excessive thermal load to the generator 10, and therefore compares the generated voltage Valt with the set voltage Vs every predetermined period. If the generated voltage Valt is equal to or higher than the set voltage Vs, the process proceeds to step S2.

  In step S <b> 2, the control unit 12 estimates the generator ambient temperature Ta, which is the overall temperature including the components of the generator 10. At this time, the control unit 12 refers to the map data describing the change in the generator ambient temperature Ta, which is the temperature characteristic of the element provided inside the regulator, with respect to the power generation voltage Valt as shown in FIG. Then, the control unit 12 estimates the generator ambient temperature Ta from the power generation voltage Valt read in step S1.

  Next, in step S3, the control unit 12 detects the rotational speed of the engine 11, and multiplies the rotational speed of the engine 11 by the speed increase ratio between the engine 11 and the generator 10, thereby The rotation speed Nd is obtained, and in step S4, the generated current Ig of the generator 10 is detected.

  As described above, the control unit 12 acquires the generator ambient temperature Ta, the rotation speed Nd of the generator 10, and the generated current Ig of the generator 10 as parameters that cause the component temperature of the generator 10 to fluctuate.

  Next, in step S5, the control unit 12 uses the parameters acquired in the preprocessing in steps S1 to S4 to refer to a temperature characteristic map stored in advance in storage means such as an internal ROM, and The component temperature Tp of 10 components is estimated.

  Here, FIGS. 4 to 6 show temperature characteristic maps. This temperature characteristic map shows the components of the regulator for the generator currents Ig1, Ig2, and Ig3 of the generator 10 when the generator ambient temperature Ta1, Ta2, Ta3 and the rotation speed N1r, N2r, N3r, and N4r of the generator 10 are changed. FIG. 7 to FIG. 9 show the relationship of changes in the temperature Tp. FIG. 7 to FIG. 9 show the power generation of the generator 10 when the generator ambient temperature Ta1, Ta2, Ta3 and the rotation speed N1r, N2r, N3r, N4r of the generator 10 are changed. The relationship of the change of the component temperature Tp of a diode with respect to electric current Ig1, Ig2, Ig3 is shown.

  Specifically, FIG. 4 shows the relationship between the regulator component temperature Tp and the generated current Ig1 when the generator ambient temperature Ta is Ta1, and FIG. 5 shows the case where the generator ambient temperature Ta is Ta2. FIG. 6 shows the relationship between the regulator component temperature Tp and the generated current Ig2, and FIG. 6 shows the relationship between the regulator component temperature Tp and the generated current Ig3 when the generator ambient temperature Ta is Ta3.

  FIG. 7 shows the relationship between the diode component temperature Tp and the generated current Ig1 when the generator ambient temperature Ta is Ta1, and FIG. 8 shows the diode component temperature when the generator ambient temperature Ta is Ta2. 9 shows the relationship between Tp and the generated current Ig2, and FIG. 9 shows the relationship between the diode component temperature Tp and the generated current Ig3 when the generator ambient temperature Ta is Ta3.

  Further, in FIGS. 4 to 9, the change in the generated current Ig of the generator 10 with respect to the generator ambient temperature Ta varies as the rotational speed Nd of the generator 10 changes to N1, N2, N3, and N4. .

  Thus, the relationship of the component temperature Tp with respect to the generator current Ig, the generator ambient temperature Ta, and the rotational speed Nd of the generator 10 is different for each component of the generator 10. 4 to 9, it has been described that the component temperatures of the regulator and the diode differ depending on the generated current Ig, the ambient temperature Ta, and the rotation speed Nd of the generator 10, but not only the regulator and the diode but also the rotor coil and the stator. For other components such as coils, a temperature characteristic map for estimating a change in component temperature is created and stored.

  The control unit 12 creates such a temperature characteristic map for each component and for each ambient temperature Ta, and stores it in advance. And the control part 12 reads the temperature characteristic map applicable to generator atmospheric temperature Ta and the component used as temperature estimation object, and if the generator rotation speed Nd and the generator current Ig of the generator 10 are acquired, the said temperature will be obtained. The component temperature Tp is estimated with reference to the characteristic map. Note that the control unit 12 determines that the generator 10 when the generator ambient temperature Ta, the rotational speed Nd of the generator 10 and the generated current Ig of the generator 10 do not simultaneously exceed a predetermined value, respectively. Since the thermal load is not excessive, the process is terminated without estimating the component temperature Tp.

  Next, in step S6, the control unit 12 compares the component temperature Tp estimated in step S5 with the set temperature Ts (first set temperature) set as the allowable temperature of each component. Here, as shown in FIGS. 4 to 9, the set temperature Ts is a temperature value that is required to suppress the power generation of the generator 10 by increasing the component temperature Tp for each component.

  If it is determined in step S6 that the component temperature Tp is equal to or higher than the set temperature Ts, the process proceeds to step S7, the voltage of the generator 10 is adjusted by the regulator, and the power generation voltage Valt of the generator 10 is changed to the battery. Reduce to below voltage. At this time, the control unit 12 gives a power generation voltage command for reducing the power generation voltage Valt of the generator 10 to the regulator. Thus, when the power generation voltage of the generator 10 decreases, the thermal load of the generator 10 decreases.

  Next, the control unit 12 returns the power generation voltage to the normal power generation voltage before decreasing the power generation voltage after a predetermined time has elapsed with the power generation voltage decreased in step S7, and in step S8, the control unit 12 performs steps S1 to S4. Process. In step S9, the control unit 12 estimates the component temperature Tp ′ of each component by referring to the temperature characteristic map using the parameter acquired in step S8.

  Next, in step S10, the control unit 12 compares the component temperature Tp 'estimated in step S9 with the set temperature Ts' (second set temperature) of each component. Here, as shown in FIGS. 4 to 9, the set temperature Ts ′ has an upper limit temperature value of the component temperature Tp ′ estimated after the power generation of the generator 10 is suppressed for a predetermined time for each component. This is a temperature obtained by subtracting the predetermined temperature α obtained from the generation voltage decrease width and generation voltage decrease time in step S7 from the set temperature Ts.

  In step S10, if the component temperature Tp ′ is lower than the set temperature Ts ′ (= Ts−α), the state is returned to normal power generation, while the component temperature Tp ′ is equal to or higher than the set temperature Ts ′. If there is, the process proceeds to step S11.

  In step S11, the control part 12 is controlled by ECU13 so that the power consumption by the electric load which is not required for driving | running | working among electric load 14A, 14B may be restrict | limited. As a result, the power required to be supplied from the battery to the electric load 14 is reduced, and the generated power required for the generator 10 is reduced.

  Furthermore, the control part 12 performs the process of step S1 thru | or step S4 as step S12, and estimates the component temperature Tp '' of each component in step S13 after progress for the fixed time which restrict | limited the electric load 14 by step S11. .

  In step S14, the control unit 12 compares the estimated component temperature Tp ″ with the set temperature Ts ′ of each component. When the component temperature Tp ″ is lower than the set temperature Ts ′, the control unit 12 Return state to power generation. On the other hand, when the component temperature Tp ″ is equal to or higher than the set temperature Ts ′, the control unit 12 continues the reduction control of the generated voltage Valt in step S7, and in step S15, the estimated component temperature Tp ″. Are compared with the set temperature Ts of each component.

  Here, when the component temperature Tp ″ is lower than the set temperature Ts, the control unit 12 repeats the processing from step S12. On the other hand, when the component temperature Tp ″ is equal to or higher than the set temperature Ts, the process proceeds to step S16, for example, the charge lamp is turned on and the power generation of the generator 10 is stopped. In step S17, Pre-processing of step S1 to step S4 is performed.

  Then, after the power generation of the generator 10 is stopped, the control unit 12 estimates the component temperature Tp ′ ″ of each component in step S18 and before the voltage decreases to a voltage that hinders traveling, and in step S19, the estimation is performed. The measured component temperature Tp ′ ″ is compared with the set temperature Ts of each component. Here, when the component temperature Tp ′ ″ is lower than the set temperature Ts, the control unit 12 resumes power generation by the generator 10 while the component temperature Tp ′ ″ is equal to or higher than the set temperature Ts. In step S20, the process proceeds to stop power generation by the generator 10.

  This generator protection process may be performed for each of one or a plurality of preset component parts, and may be performed for each component part. Furthermore, not only a regulator or a diode, but also a rotor coil or a stator coil. Needless to say, the overload determination is performed in consideration of the above.

[Effect of the embodiment]
As described above in detail, according to the control unit 12 to which the present invention is applied, the generator ambient temperature Ta based on the generated voltage of the generator 10, the rotational speed Nd of the generator 10, and the generated current Ig of the generator 10 are A temperature characteristic map showing a change in the component temperature Tp with respect to the change is stored, and the temperature characteristic map is based on the actually detected generator ambient temperature Ta, the rotational speed Nd of the generator 10, and the generated current Ig of the generator 10. Therefore, it is not necessary to provide a sensor for detecting the temperature in the generator 10, and not only for the regulator but also for each other component such as a diode. The optimum generator overload determination can be performed in consideration of the component temperature, and high-precision protection of the generator 10 can be realized. Therefore, according to the control unit 12, even when it is determined that the generator ambient temperature Ta, which is the temperature of the regulator, is low and the thermal load of the regulator is low, the thermal components of the other generators 10 If it is determined that the load is high, the generator 10 can be protected.

  Specifically, at least one temperature characteristic map of a regulator, a semiconductor element, a rotor coil, or a stator coil that is a component of the generator 10 is stored, and at least the regulator, the semiconductor element, the rotor coil, or the stator coil is stored. By estimating one of the component temperature with reference to one or more temperature characteristic maps, the thermal load of the generator 10 can be estimated with high accuracy, and the component can be reliably protected.

  Further, according to the control unit 12, when it is estimated that the component temperature Tp is higher than the set temperature Ts, the power generation voltage of the generator 10 is reduced below the voltage of the battery. When the thermal load becomes high, the thermal load of the component can be reliably reduced.

  Furthermore, according to this control unit 12, when the component temperature Tp is estimated to be higher than the set temperature Ts ′ after the power generation voltage of the generator 10 is lowered, the generated power of the generator 10 is increased. Since the electric power supply to any one of the electric loads 14 is restricted, the generated voltage required for the generator 10 can be reliably reduced. Further, even if the power generation voltage of the generator 10 is reduced, it is possible to reliably protect the components that do not reduce the component temperature Tp. Moreover, even if it is a case where the thermal load of the generator 10 is reduced by giving priority to stopping the electric load 14 which is not related to vehicle driving as the electric load 14, it can be made to have no influence on vehicle driving.

  Furthermore, according to the control unit 12, after the supply of electric power to any one of the electric loads 14 is restricted, the power generation by the generator 10 is performed when it is estimated that the component temperature Tp is higher than the set temperature Ts ′. Therefore, it is possible to reliably protect the components whose component temperature Tp does not decrease even if the power supply of the electric load 14 is limited.

  Furthermore, according to the control unit 12, when the component temperature is estimated to be higher than the set temperature Ts after the power generation of the generator 10 is stopped, the power generation stop of the generator 10 is continued. Even if the power generation of the machine 10 is temporarily stopped, it is possible to more reliably protect the component parts whose temperature does not decrease.

  The above-described embodiment is an example of the present invention. For this reason, the present invention is not limited to the above-described embodiment, and even if it is a form other than this embodiment, as long as it does not depart from the technical idea of the present invention, it depends on the design and the like. Of course, various modifications are possible.

  Further, the “rotation speed detecting means” in the claims corresponds to the “processing function in step S3 of the control unit 12” in the embodiment, and the “current detection means” in the claims is the “control unit in the embodiment”. The “voltage detection means” in the claims corresponds to the “voltage detection function in step S1 of the control unit 12” in the embodiment. The “generator ambient temperature calculation means” corresponds to “the processing function of the control unit 12 in step S2” in the embodiment, and the “storage means” in the claims refers to the “internal ROM of the control unit 12 (step S5). The “estimating means” in the claims is “step S5 of the control unit 12, step S9, step S13, It corresponds to the processing function "in step S18, the" control unit in the claims, "the step S7 of the" control portion 12 in the embodiment, step S11, step S16, corresponds to the processing function "in step S20.

It is a block diagram which shows the structure of the vehicle electrical system shown as embodiment of this invention. In a vehicle electrical system, it is a flowchart which shows a series of processes at the time of performing overload determination for every component which comprises a generator, and controlling the electric power generation by a generator. It is a figure which shows the relationship of the atmospheric temperature with respect to the power generation voltage of a generator as a temperature characteristic of the element provided in a regulator. It is a figure which shows the change of the component temperature of a regulator with respect to generator atmosphere temperature Ta1, the rotation speed of a generator, and the electric power generation electric current of a generator. It is a figure which shows the change of the component temperature of a regulator with respect to generator atmospheric temperature Ta2, the rotation speed of a generator, and the electric power generation electric current of a generator. It is a figure which shows the change of the component temperature of a regulator with respect to generator atmospheric temperature Ta3, the rotation speed of a generator, and the electric power generation electric current of a generator. It is a figure which shows the change of the component temperature of a diode with respect to generator atmospheric temperature Ta1, the rotation speed of a generator, and the electric power generation electric current of a generator. It is a figure which shows the change of the component temperature of a diode with respect to generator atmospheric temperature Ta2, the rotation speed of a generator, and the electric power generation electric current of a generator. It is a figure which shows the change of the component temperature of a diode with respect to generator atmospheric temperature Ta3, the rotation speed of a generator, and the electric power generation electric current of a generator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Generator 11 Engine 12 Control part 13 ECU
14A, 14B Electric load Ig Generated current Nd Rotation speed Ta Atmospheric temperature Tp, Tp ', Tp'',Tp''' Component temperature Ts, Ts' Set temperature Valt Generated voltage Vs Set voltage

Claims (7)

A rotational speed detection means for detecting the rotational speed of the generator;
Current detection means for detecting the generated current of the generator;
Voltage detection means for detecting the power generation voltage of the generator;
A generator ambient temperature calculating means for calculating a generator ambient temperature based on the generated voltage of the generator detected by the voltage detecting means;
With respect to changes in the generator rotational temperature detected by the rotational speed detection means, the generator current detected by the current detection means, and the generator ambient temperature calculated by the generator ambient temperature calculation means Storage means for storing a temperature characteristic map showing a change in temperature of the component parts of the generator;
Based on the rotational speed of the generator detected by the rotational speed detection means, the generated current of the generator detected by the current detection means, and the generator ambient temperature calculated by the generator ambient temperature calculation means. , Referring to the temperature characteristic map stored in the storage means, estimating means for estimating the component temperature of the generator;
And a control means for controlling the operation of the generator based on the component temperature of the generator estimated by the estimating means.   When the component temperature of the generator estimated by the estimation unit is higher than a first set temperature, the control unit is configured to use a power generation voltage of the generator as a battery for charging power generated by the generator. The generator protection device according to claim 1, wherein the generator protection device is lowered to a voltage or lower.   The control means reduces the power generation voltage of the generator and then generates power when the component temperature of the generator estimated by the estimation means is also higher than a second set temperature lower than the first set temperature. The generator protection device according to claim 2, wherein supply of electric power to any one of the electric loads to which the electric power generated by the electric machine is supplied is limited.   The control means restricts the supply of power to any electric load, and then, when the component temperature of the generator estimated by the estimation means is higher than the first set temperature, the power generation The generator protection device according to claim 3, wherein power generation of the generator is stopped.   The control means stops the power generation of the generator when the component temperature of the generator estimated by the estimation means is higher than the first set temperature after stopping the power generation of the generator. The generator protection device according to claim 4, wherein the generator is continued. The storage means stores a temperature characteristic map of at least one of a regulator, a semiconductor element, a rotor coil, or a stator coil that are components of the generator,
The estimation means estimates the temperature of any component by referring to at least one temperature characteristic map of a regulator, a semiconductor element, a rotor coil, or a stator coil, which are components of the generator. The generator protection device according to any one of claims 1 to 5. Detecting the rotational speed of the generator, the generated current of the generator, and the generated voltage of the generator when generating power by the generator;
Calculating an ambient temperature of the generator based on the generated voltage of the generator;
Reading a temperature characteristic map stored in advance in storage means indicating changes in component temperature of the generator with respect to changes in the number of revolutions of the generator, the generated current of the generator, and the ambient temperature of the generator;
Estimating component temperature of the generator by referring to the temperature characteristic map based on the actually detected rotation speed of the generator, the generated current of the generator, and the ambient temperature of the generator When,
And a step of controlling the operation of the generator based on the estimated component temperature of the generator.

Images