JPH11230997A - Voltage sensor for electric automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small and inexpensive insulated voltage sensor for electric automobile. SOLUTION: A light emitting diode 11 emits light when a voltage is applied from a stabilized power supply 5 and the light is received by photodiodes 13, 15. An operational amplifier 7 is driven with the voltage from the stabilized power supply to amplify the voltage of a battery power supply 2b and a feedback voltage from the photodiode 13 and controls the output from the light emitting diode based on the amplified voltage. An operational amplifier 17 is driven with the voltage from a battery power supply for communication system to integrate a voltage based on the light receiving outputs across the photodiode 15 and outputs the integrated voltage as a detection voltage corresponding to the voltage of the battery power supply for power system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated voltage sensor for an electric vehicle which detects a high-current voltage applied to a motor for operating the electric vehicle in a non-contact manner using a photocoupler.

[0002]

2. Description of the Related Art Conventionally, in an electric vehicle, an electric vehicle is run by supplying a voltage from a high-power battery (battery) to a motor and rotating the motor. In this case, in order to insulate and measure the voltage of a high-power battery, a voltage sensor to which the zero magnetic flux method shown in FIG. 13 (refer to the July 1989 sensor technology) is generally used.

[0003] The voltage sensor 101 shown in FIG. 13 has a magnetic core 103, and the magnetic core 103 has a primary winding 10.
5 and the secondary winding 107 are wound, and the primary winding 10
5 includes a plurality of power supplies 111a, 111 via a resistor 109.
.. 111n are connected in series. In the gap 113 formed in the magnetic core 103, a Hall element 115 is provided.

In this case, a magnetic flux is generated in the magnetic core 103 by the primary current I ₁ flowing through the primary winding 105, and the Hall element 115 for detecting the magnetic field depends on the direction of the magnetic field and the magnitude of the magnetic field Φ _1. A voltage is generated and the current amplifier 11
7 is output. The current amplifier 117 includes the Hall element 115
The output current I ₂ flows through the secondary winding 107 by amplifying the current based on the voltage from When the output current I ₂ flows through the secondary winding 107, a magnetic flux Φ ₂ is generated. In this case, act as magnetic flux Φ ₂ is cancel the magnetic flux Φ _1.

[0005] When the magnetic flux [Phi ₂ becomes equal to the magnetic flux [Phi _1, flux [Phi ₁ in the magnetic core 103 becomes zero. Accordingly, the Hall element 115 makes the output zero, and the magnetic flux Φ
_{2 is} also zero. In this state, the magnetic flux Φ ₁ is generated again in the magnetic core 103 and the Hall element 115
The magnetic flux Φ ₂ is larger than the magnetic flux Φ ₁ in the magnetic core 103. This operation is repeated at a high frequency, the output current I ₂ is the effective value conversion. At this time, the following ampere-turn rule is established.

N ₁ I ₁ = N ₂ I _{2 Using} this equation, the output current I ₂ from the current amplifier 117
Is measured, the primary current I ₁ is obtained. Further, the detected voltage across the resistor 119 is a voltage proportional to the output current I _2.

[0007]

However, in the conventional voltage sensor, although high accuracy, the magnetic core 10
3. Since the primary winding 105 and the secondary winding 107 are provided, there has been a problem that the voltage sensor becomes large and expensive.

In recent years, in electric vehicles, the development of batteries has progressed, and as the charge / discharge function has become more sophisticated, demands for battery voltage management have become more stringent. For example, the number of strong current batteries in the drive system is 20 to 3
About 0 batteries are connected in series, and voltage management of the single battery is required.

For this reason, the number of voltage sensors required is equal to the number of batteries, and if a conventional voltage sensor is used, the size of the voltage sensor is further increased. Further, in an electric vehicle, it is necessary to insulate the strong electric system and the weak electric system of the electric vehicle in order to prevent electric shock, electric leakage, and noise.

An object of the present invention is to provide a small, inexpensive and insulative voltage sensor for electric vehicles.

[0011]

The present invention has the following arrangement to solve the above-mentioned problems. According to a first aspect of the present invention, there is provided a voltage sensor for an electric vehicle, a stabilized power supply for stabilizing a voltage of a battery power supply of a strong electric system, a light emitting element which emits light by the voltage of the stabilized power supply, and receives light of the light emitting element. A first light receiving element and a second light receiving element are driven by a voltage of the stabilized power supply, and amplify a voltage of the battery power supply and a feedback voltage fed back from the first light receiving element to an amplified voltage. A differential amplifier circuit that controls the light emission output of the light emitting element based on the voltage of a battery power supply of a weak current system, and integrates and integrates a voltage based on the light reception output input from both ends of the second light receiving element. And an integrating circuit for outputting the detected voltage as a detection voltage corresponding to the voltage of the battery power supply of the high-power system.

According to the first aspect of the present invention, when the voltage of the battery power of the high-power system stabilized by the stabilized power supply is supplied to the light emitting element, the light emitting element emits light and the light of the light emitting element is changed to the first light. The light receiving element and the second light receiving element receive light.

The differential amplifier circuit amplifies the voltage of the battery power supply and the feedback voltage fed back from the first light receiving element, and controls the light emission output of the light emitting element based on the amplified voltage. At this time, since the second light receiving element also performs the same operation as the first light receiving element, the integrating circuit integrates a voltage based on the light receiving output input from both ends of the second light receiving element, and integrates the integrated voltage. Is output as a detection voltage corresponding to the voltage of the battery power supply of the high-power system. Further, since the strong current system and the weak current system are insulated from each other, it is possible to provide a small-sized and inexpensive voltage sensor having an insulating property.

According to a second aspect of the present invention, there is provided a voltage sensor for an electric vehicle which is provided in one-to-one correspondence with each of a plurality of series-connected battery power supplies of a high-power system, and a terminal voltage of the battery power supply. A plurality of voltage detectors, each of the voltage detectors includes a stabilized power supply for stabilizing the voltage of the high-power battery power supply, a light-emitting element that emits light by the voltage of the stabilized power supply, and a light-emitting element. A first light-receiving element and a second light-receiving element that receive light of the same, and driven by a voltage of the stabilized power supply, and a voltage of the battery power supply and the first light-receiving element.
A differential amplifier circuit that amplifies a feedback voltage fed back from the light receiving element and controls a light emitting output of the light emitting element based on the amplified voltage; An integration circuit that integrates a voltage based on a light receiving output input from both ends of the element and outputs the integrated voltage as a detection voltage corresponding to a voltage of the high-power battery power supply.

According to the second aspect of the present invention, the voltage sensor comprises:
Since it is provided for each battery power source, the single voltage of each battery power source of the plurality of battery power sources can be measured.

According to a third aspect of the present invention, there is provided a voltage sensor for an electric vehicle for detecting a total voltage of a plurality of series-connected high-power battery power supplies, wherein the stabilized power supply and the voltage of the stabilized power supply are used. A light-emitting element that emits light, a first light-receiving element and a second light-receiving element that receive light from the light-emitting element, and are driven by the voltage of the stabilizing power supply. A differential amplifier circuit for amplifying a feedback voltage fed back from the first light receiving element and controlling a light emitting output of the light emitting element based on the amplified voltage; An integrating circuit that integrates a voltage based on a light receiving output input from both ends of the light receiving element, and outputs the integrated voltage as a detection voltage corresponding to the voltage of the plurality of high-power battery power supplies. To be

According to the third aspect of the present invention, the integration circuit outputs a detection voltage corresponding to a voltage of a plurality of high-power battery power supplies. It is possible to detect the total voltage of the high-power battery power supply, and to provide a compact and inexpensive voltage sensor.

According to a fourth aspect of the present invention, the stabilized power supply stabilizes the total voltage of the plurality of high-power battery power supplies, and applies the stabilized voltage to the differential operation amplifier circuit and the light emitting element. It is characterized by supplying.

According to the invention of claim 4, the stabilized power supply comprises:
Since the total voltage of a plurality of high-power battery power supplies is stabilized and the stabilized voltage is supplied to the differential operation amplifier circuit and the light emitting element, the differential operation amplifier circuit and the light emitting element can be operated by the high current power supply. it can.

According to a fifth aspect of the present invention, the stabilized power supply converts the voltage of the weak electric power supply into the voltage of the high electric power supply through insulation, and converts the converted voltage of the high electric power supply. A voltage of a power supply is supplied to the differential operation amplifier circuit and the light emitting element.

According to the invention of claim 5, the stabilized power supply comprises:
The voltage of the battery power of the weak electric system is converted into the voltage of the battery power of the strong electric system via insulation, and the converted voltage of the battery power of the strong electric system is supplied to the differential operation amplifier circuit and the light emitting element. The differential operation amplifier circuit and the light emitting element can be operated by the power supply of the high-power system without receiving the voltage from the battery power supply of the plurality of high-power systems. The breakdown voltage of the element can be low.

According to a sixth aspect of the present invention, there is provided a voltage sensor for an electric vehicle, comprising: a strong electric power stabilized power supply for stabilizing a terminal voltage of a strong electric power battery;
A voltage frequency converter that converts a terminal voltage of the high-power battery to a frequency corresponding to the voltage, a voltage of the high-power stabilizing power supply is supplied to an input side, and a voltage of a weak power supply is supplied to an output side, An insulating unit that outputs a frequency converted by the voltage frequency converter in a state where the input side and the output side are insulated from each other as a detection output corresponding to a terminal voltage of the high-voltage battery. .

According to the sixth aspect of the present invention, the voltage frequency converter operated by the voltage of the strong current stabilized power supply converts the terminal voltage of the strong current battery into a frequency corresponding to the voltage,
In the insulation part, the voltage of the high-voltage stabilized power supply is supplied to the input side, the voltage of the low-voltage power supply is supplied to the output side, and the frequency converted by the voltage frequency converter with the input side and the output side insulated. Is output as a detection output corresponding to the terminal voltage of the high-power battery, so that it is possible to provide a compact, inexpensive and insulated voltage sensor.

According to a seventh aspect of the present invention, there are provided a plurality of voltage detecting sections provided in one-to-one correspondence with the respective high-current batteries of the plurality of high-current batteries connected in series, and each voltage detecting section comprises: Operates with a high-voltage stabilizing power supply that stabilizes the terminal voltage of the high-voltage battery and the voltage of this high-voltage stabilizing power supply.
A voltage frequency converter that converts a terminal voltage of the high-power battery to a frequency corresponding to the voltage, a voltage of the high-power stabilizing power supply is supplied to an input side, and a voltage of a weak power supply is supplied to an output side, An insulating unit that outputs a frequency converted by the voltage frequency converter in a state where the input side and the output side are insulated from each other as a detection output corresponding to a terminal voltage of the high-voltage battery. .

According to the invention of claim 7, the voltage sensor comprises:
Since a plurality of high-power batteries are provided for each high-power battery, a frequency corresponding to a single voltage of the high-power battery can be output for each high-power battery.

The invention according to claim 8 is characterized in that, when the terminal voltage of the high-current battery is detected, when the low-current power supply operates.
A voltage supply control unit that operates with the voltage of the weak electric power supply and supplies a terminal voltage of the strong electric power battery to the strong electric power stabilized power supply is provided.

According to the eighth aspect of the present invention, the voltage supply control unit operates with the voltage of the weak electric power supply when detecting the terminal voltage of the strong electric power battery, and converts the terminal voltage of the strong electric power battery to the strong electric power stabilized power supply. Since the power supply is stabilized,
The voltage frequency converter and the insulating unit are operated when the terminal voltage of the strong current battery is detected. For this reason, it is possible to eliminate the dark current flowing at times other than the time of detecting the voltage of the strong current battery, thereby preventing the discharge of the strong current battery.

According to a ninth aspect of the present invention, there is provided a voltage sensor for an electric vehicle for detecting a total voltage of a plurality of series-connected high-power batteries, and operates with a stabilized power supply and a voltage of the stabilized power supply. A voltage frequency converter for converting the total voltage of the plurality of high-voltage batteries into a frequency corresponding to the voltages, a voltage of the stabilized power supply being supplied to an input side, and a voltage of a weak power supply being supplied to an output side An insulation unit that outputs the frequency converted by the voltage frequency converter in a state where the input side and the output side are insulated from each other, as a detection output corresponding to the total voltage of the plurality of high-voltage batteries. It is characterized by having.

According to the ninth aspect of the present invention, the insulating section outputs the frequency converted by the voltage frequency converter as a detection output corresponding to the total voltage of the plurality of high-voltage batteries.
Since only one voltage sensor is required, a more compact and inexpensive voltage sensor can be provided.

According to a tenth aspect of the present invention, when the weak electric power supply operates when detecting the total voltage of the plurality of strong electric power batteries, the plurality of strong electric power batteries operate by the voltage of the weak electric power supply. And a voltage supply control unit for supplying the total voltage to the stabilized power supply.

According to the tenth aspect of the present invention, it is possible to eliminate a dark current flowing at times other than the time of detecting the voltage of the high-power battery, thereby preventing the discharge of the high-power battery.

According to the eleventh aspect of the present invention, the stabilized power supply stabilizes the total voltage of the plurality of high-voltage batteries and outputs the stabilized voltage to the input side of the voltage frequency converter and the insulating unit. Is supplied.

According to the eleventh aspect of the present invention, the stabilized power supply stabilizes the total voltage of the plurality of high-voltage batteries and supplies the stabilized voltage to the input side of the voltage frequency converter and the insulating unit. The voltage-frequency converter and the input side of the insulating unit can be operated by a power supply of a strong electric system.

According to a twelfth aspect of the present invention, the stabilized power supply converts the voltage of the weak electric power supply into the voltage of the strong electric power supply through insulation, and converts the converted voltage of the strong electric power supply to the voltage. The power is supplied to the input side of the frequency converter and the insulating unit.

According to the twelfth aspect of the present invention, the stabilized power supply converts the voltage of the weak electric power supply to the voltage of the strong electric power supply via insulation, and converts the converted voltage of the strong electric power supply to a voltage frequency converter and Since it is supplied to the input side of the insulation unit, it insulates between the high-voltage system and the low-voltage system, and does not receive the voltage from multiple high-voltage batteries. Can be operated, and the withstand voltage on the input side of the voltage frequency converter and the insulating portion can be low.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the voltage sensor for electric vehicles according to the present invention will be described in detail with reference to the drawings.

<First Embodiment> FIG. 1 is a circuit diagram showing a first embodiment of a voltage sensor for an electric vehicle according to the present invention. In the voltage sensor 1 shown in FIG. 1, there is provided a high-power battery 2 configured by connecting a plurality of batteries 2a, 2b, 2c,.
Constitutes a primary-side circuit power supply, applies a high voltage to the motor, rotates the motor, and drives the electric vehicle.

A resistor 3a and a resistor 3 are provided at both ends of the battery 2b.
b are connected in series, and a high-voltage stabilizing power supply 5 for stabilizing the voltage from the battery 2b is connected to the positive electrode side of the battery 2b and one end of the resistor 3a.
The connection point between the other end of the resistor 3a and one end of the resistor 3b is
Is connected to the inverting input terminal (-) of the operational amplifier 7 constituting the first differential amplifier circuit, and the other end of the resistor 3b is connected to the negative electrode side of the battery 2b and the ground.

A capacitor 8 for negative feedback is connected between the inverting input terminal (-) of the operational amplifier 7 and the output of the operational amplifier 7, and the non-inverting input terminal (+) of the operational amplifier 7 is connected to the negative side of the battery 2b and the ground. It is connected to the.

The output of the stabilized power supply 5 is supplied to an operational amplifier 7 and a photocoupler integrated circuit (hereinafter, referred to as a photocoupler IC) 9. The photocoupler IC9 includes a light emitting diode 11, a photodiode 13, and a photodiode 15. The light emitting diode 11 and the photodiode 13 constitute an input side which is a primary side,
The photodiode 15 forms an output side which is a secondary side. The primary side and the secondary side are insulated.

The anode of the light emitting diode 11 is connected to the port P
1 is connected to the stabilized power supply 5 through the light emitting diode 1
The cathode of 1 is connected to the output side of the operational amplifier 7 via the port P2. The cathode of the photodiode 13 on the primary side is connected to the inverting input terminal (-) of the operational amplifier 7 via the port P3, and the anode of the photodiode 13 is grounded via the port P4. The photodiode 13 and the photodiode 15 are the light emitting diode 11
Receives the light emitted by.

The cathode of the photodiode 15 on the secondary side is connected to the inverting input terminal (-) of the operational amplifier 17 constituting the second differential amplifier circuit via the port P6, and the anode of the photodiode 15 is connected to the port It is connected to the non-inverting input terminal (+) of the operational amplifier 17 via P5 and is grounded. The operational amplifier 17 is operated by a weak electric power source and amplifies a voltage difference between both ends of the photodiode 15. Ports P7 and P8 of photocoupler 9
Is an unconnected terminal (NC).

The output side of the operational amplifier 17 and the operational amplifier 17
A resistor 19 is connected between the inverting input terminal and a resistor 21. A capacitor 21 is connected in parallel with the resistor 19,
And the capacitor 21 constitute an integrating circuit. On the output side of the operational amplifier 17, a voltage Vout corresponding to the voltage of the battery 2b is output.

Next, the first embodiment thus configured
The operation of the electric vehicle voltage sensor will be described. First, the voltage of the battery 2b in the high-power system battery 2 is stabilized by the stabilized power supply 5, and the voltage from the stabilized power supply 5 is applied to the operational amplifier 7 and the light emitting diode 1 in the photocoupler IC9.
1 is applied to the anode.

At the same time, the voltage of the battery 2b is divided by the resistors 3a and 3b, and the divided voltage at the connection point between the resistors 3a and 3b is applied to the inverting input terminal of the operational amplifier 7 via the resistor 6. Is input to Then, when the light emitting diode 11 in the photocoupler IC 9 emits light and turns on, the light of the light emitting diode 11 is
Receives light and turns on.

Further, since a relatively low voltage due to the turning on of the photodiode 13 is input to the inverting input terminal of the operational amplifier 7, the input voltage of the inverting input terminal of the operational amplifier 7 decreases. Then, since the output voltage of the operational amplifier 7 is higher than the initial voltage, the light emitting diode 11 is turned off.

Then, the photodiode 13 is turned off when the light emitting diode 11 is turned off, and a relatively high voltage due to the turning off of the photodiode 13 is input to the inverting input terminal of the operational amplifier 7. Voltage rises. Then, since the output voltage of the operational amplifier 7 returns to the initial voltage, the light emitting diode 11 turns on.

That is, the light emitting diode 11 and the photodiode 13 are repeatedly turned on and off by a feedback loop including the operational amplifier 7, the light emitting diode 11, and the photodiode 13. Thereby, the light emission output of the light emitting diode 11 is controlled.

On the other hand, since the photodiode 15 also has the same characteristics as the photodiode 13, when the light emitting diode 11 emits light, the light from the light emitting diode 11 is received by the photodiode 15. That is, the secondary-side photodiode 15 performs the same operation as the operation of the photodiode 13 in accordance with the on / off operation of the primary-side light emitting diode 11.

When the light receiving output of the photodiode 15 is input to the operational amplifier 17, the output is integrated and amplified by the operational amplifier 17 and an integrating circuit including the resistor 19 and the capacitor 21, and is amplified. Has a voltage output Vout corresponding to the voltage of the battery 2b.
Is output.

As described above, according to the voltage sensor 1 of the first embodiment, since it is constituted by using the photocoupler, it is smaller in size, cheaper and more insulative than the voltage sensor using the zero magnetic flux method. Can be provided. Further, the accuracy of the detection voltage can be almost the same as that of the zero magnetic flux method.

Next, FIG. 2 shows a circuit configuration diagram of a strong electric system and a weak electric system in the electric vehicle. In FIG. 2, a high-power battery 2 supplies power to a voltage sensor 1 using a photocoupler and a motor controller driver 31, and the motor controller driver 31 drives the motor 33 to rotate by the power from the high-power battery 2. .

The current sensor 35 detects a current I ₃ flowing through a signal line connecting the high-voltage battery 2 and the motor 33 via the motor controller driver 31, and outputs the detected current to the battery controller 27. The battery controller 27 controls the voltage value from the voltage sensor 1 and the current sensor 35
It manages the voltage and temperature of the battery based on the current value from the battery. The weak electric system battery 41 is, for example, an auxiliary battery used to drive a 12 V system auxiliary device, and supplies power to the weak electric system device 39 and the battery controller 37.

With the above configuration, the strong current battery 2 and the weak current battery 41 are electrically insulated from each other via the voltage sensor 1 using a photocoupler. Therefore, there is no electric shock or electric leakage, and noise can be reduced.

FIG. 3 shows a voltage monitoring device including a voltage sensor and a battery controller. The voltage monitoring device includes a voltage sensor 1, a battery controller 37, a battery cooling fan 43,
It comprises a charger 45, a motor controller 47, and a meter 49. The voltage sensor 1, the battery cooling fan 43, the charger 45, the motor controller 47, and the meter 49 are connected to the battery controller 37.

The battery controller 37 constitutes a battery control unit, receives a voltage value from the voltage sensor 1, constantly monitors the state of the voltage of the battery 2b, and controls the voltage of the battery 2b to be an optimum voltage. I do. That is, when the voltage of the battery 2b falls below a predetermined voltage based on the voltage value from the voltage sensor 1, the battery controller 37 outputs a charge control signal to the charger 45. To charge the battery 2b to a predetermined voltage. This makes it possible to manage the voltage of the battery 2b so as not to drop below the predetermined voltage.

Further, the battery controller 37 outputs a discharge control signal and a regenerative control signal to the motor controller 47 based on the voltage value from the voltage sensor 1, so that the motor controller 47 controls the discharge of the battery 2b to the motor 33. For example, when the electric vehicle goes down a hill or the like, the regeneration control of the electric power from the motor 33 to the battery 2b is performed. Thereby, the amount of electricity stored in the battery 2b can be effectively used.

Further, the battery controller 37 operates the battery cooling fan 43 based on the voltage value from the voltage sensor 1 to manage the temperature of the battery 2b. For example, when the voltage value from the voltage sensor 1 is higher than a predetermined voltage value, the battery controller 37
3 can be controlled so that the temperature of the battery 2b becomes constant.

The battery controller 37 outputs a warning indicator signal to the meter 49 when the voltage value from the voltage sensor 1 becomes lower than the predetermined voltage value, and the voltage of the battery 2b drops below the predetermined voltage. It can alert you.

<Second Embodiment> Next, a second embodiment of the voltage sensor for an electric vehicle according to the present invention will be described. FIG. 4 shows an electric vehicle voltage sensor according to a second embodiment for measuring the total voltage of a plurality of batteries connected in series. In FIG. 4, the high-power battery 2 has a voltage of, for example, 288 V, and is composed of batteries 2 a, 2 b, 2 c... 2 n connected in series, and each battery has a voltage of, for example, 12 V. One end of the voltage sensor 1 is connected to the positive electrode side of the battery 2a,
The other end of the voltage sensor 1 is connected to the negative electrode side of the battery 2n.

According to this configuration, the total voltage of the batteries 2a, 2b, 2c... 2n connected in series can be measured by the voltage sensor 1, and since there is only one voltage sensor 1, the size and the size can be further reduced. It will be cheaper.

Next, three specific examples of the voltage sensor of the second embodiment, that is, voltage sensors for measuring the total voltage of a plurality of batteries connected in series will be described.

(Embodiment 1) First, FIG. 5 shows a circuit configuration diagram of Embodiment 1 of a voltage sensor for measuring the total voltage of a plurality of batteries connected in series. In FIG. 5, points P and N
Between the high-power battery 2 (for example, 288
V), and between point P and point N,
Resistance R1, R2, R16, R3, R4, R12, R15
Is connected, and one end of the resistor R13 and the point N are grounded.

A stabilizing power supply 5a is connected to the point P. The stabilizing power supply 5a stabilizes the voltage of the high-voltage battery 2 of 288 V, and outputs the stable voltage of the high-voltage system to the operational amplifier 51, the operational amplifier 7, the light emitting diode 11 To the anode.

The connection point between the resistors R4 and R12 is connected to the non-inverting input terminal of the operational amplifier 51.
1 is directly connected to the inverting input terminal and the output terminal, and a capacitor 52 is connected between the power supply of the operational amplifier 51 and the ground to form a voltage follower circuit.

The resistor 53 is connected between the output terminal of the operational amplifier 51 and the inverting input terminal of the operational amplifier 7.
One end of the resistor 4 is connected to the output terminal of the operational amplifier 51, and the other end of the resistor 54 is grounded.

Next, a differential amplifier circuit including an operational amplifier 7,
The configuration of the integration circuit including the photocoupler IC9 and the operational amplifier 17 is substantially the same as the configuration shown in FIG. 1, and therefore, the same portions are denoted by the same reference numerals and description thereof will be omitted. 1, a resistor 10 connected between the output terminal of the operational amplifier 7 and the cathode of the light emitting diode 11, a capacitor 18 connected between the power supply of the operational amplifier 17 and the ground, and an output terminal of the operational amplifier 17 The difference is that a resistor 20 connected between the ground and the ground is provided.

Further, a power supply 60 of a weak current system is provided for operating the operational amplifier 17. This power supply 60
It converts + 12V of the weak current system to + 5V of the weak current system and supplies the converted voltage to the operational amplifier 17, and is configured as follows.

The anode of the diode 61 is connected to +12 V of the weak electric system, the cathode is connected to one end of the capacitors 62 and 63, and the pulse duty ratio is set to + 12V.
It is connected to the input side of a switching regulator (REG) 64 that converts 12V to + 5V. A capacitor 65 is connected to the output side of the switching regulator 64, and the output is supplied to the operational amplifier 17 as a weak power supply.

Next, the operation of the first embodiment configured as described above will be described. First, the stabilized power supply 5a stabilizes the voltage (288 V) of the high-voltage battery 2 and directly applies the high-voltage to the operational amplifier 51, the operational amplifier 7, and the light-emitting diode 1.
1, the operational amplifier 51, the operational amplifier 7, and the light emitting diode 11 operate. In this case, the operational amplifier 5
1. The operational amplifier 7 and the light emitting diode 11 need to withstand high voltage. In addition, since the voltage of the high-current system is directly supplied to the operational amplifier 51, the operational amplifier 7, and the light emitting diode 11, it is not insulated.

Next, the voltage of the high-current system at the resistor R12 is input to the non-inverting input terminal of the operational amplifier 51, and the voltage of the operational amplifier 5
The output voltage of the operational amplifier 51 is converted from high impedance to low impedance by 1 and the output voltage of the operational amplifier 51 is input to the inverting input terminal of the operational amplifier 7 via the resistor 53.

Then, the operational amplifier 7, the photocoupler IC
9. The operational amplifier 17 operates as described in the operation of the first embodiment. That is, the light emitting diode 11 and the photodiode 13 are repeatedly turned on and off by a feedback loop including the operational amplifier 7, the light emitting diode 11, and the photodiode 13. The photodiode 15 performs the same operation as the operation of the photodiode 13 according to the on / off operation of the light emitting diode 11.

When the output of the photodiode 15 is input to the operational amplifier 17, the output is integrated and amplified by the operational amplifier 17 and an integrating circuit including the resistors 19, 20 and 21. That is, the operational amplifier 17 obtains a divided voltage corresponding to the combined resistance of the resistor R12 and the resistor R15, and determines the divided voltage, the combined resistance, and the total resistance (the total resistance from the resistor R1 to the resistor 15) based on the divided voltage. The total voltage is obtained, and this total voltage is output as a voltage output Vou.
It can be output as t.

(Embodiment 2) First, FIG. 6 shows a circuit configuration diagram of Embodiment 2 of a voltage sensor for measuring the total voltage of a plurality of batteries connected in series. The second embodiment is characterized in that a DC-DC converter 55 is provided in place of the stabilized power supply 5a of the first embodiment.

The DC-DC converter 55 is a
For example, a transformer for converting 12V into + 5V or + 12V of a strong electric system is used to insulate the weak electric system from the strong electric system. A capacitor 56 and a switching regulator 58 are connected to the output of the DC-DC converter 55,
The output of the switching regulator 58 (for example, +5 V of the high-current system, P of 5 P in FIG. 6 indicates a high-current system) is supplied to the operational amplifier 51, the operational amplifier 7, and the light emitting diode 11.

Since the other configuration is the same as that of the first embodiment, the same portions are denoted by the same reference numerals and detailed description thereof will be omitted.

As described above, according to the second embodiment, the DC-DC
The converter 55 converts the weak electric system + 12V to the strong electric system +5.
Since the voltage is converted to V, it is possible to obtain a stabilized power supply of the strong electric system through the insulation of the weak electric system. Further, since the operational amplifier 51, the operational amplifier 7, and the light emitting diode 11 are operated by the converted voltage of the high-current system, the breakdown voltages of these elements may be low.

(Embodiment 3) First, FIG. 7 shows a circuit configuration diagram of Embodiment 3 of a voltage sensor for measuring the total voltage of a plurality of batteries connected in series. The third embodiment is characterized in that an insulated power supply 70 using a multivibrator is provided in place of the stabilized power supply 5a of the first embodiment.

The insulated power supply 70 converts +12 V of the weak electric system to +5 V or +12 V of the strong electric system, and insulates the weak electric system from the strong electric system. The operational amplifier 71 is supplied with +12 V of a weak current system, a capacitor 72 is connected between the inverted input terminal of the operational amplifier 71 and the ground, and a resistor 73 is connected between the inverted input terminal and the output terminal of the operational amplifier 71. You.

A resistor 74 is connected between the non-inverting input terminal of the operational amplifier 71 and the ground, and a resistor 75 is connected between the non-inverting input terminal and the output terminal of the operational amplifier 71 to form a multivibrator. I have.

The output of the operational amplifier 71 is connected to the base of the transistor 77 via the resistor 76, and the collector is +1
2V, and the emitter is connected to one end of the primary winding of the transformer 78. The other end of the primary winding of the transformer 78 is grounded. The transformer 78 insulates the primary side weak current system from the secondary side strong current system. One end of the secondary winding of the transformer 78 is connected to the anode of the diode 79 and the cathode of the diode 81.
9 and the other end of the secondary winding between the capacitor 8
0 is connected.

A capacitor 82 is connected between the other end of the secondary winding and the anode of the diode 81.
One end of 3 is connected to the cathode of diode 79. The other end of the capacitor 83, the anode of the diode 81, and one end of the capacitor 82 are grounded.

A switching regulator 84 is connected to the cathode of the diode 79. The output of the switching regulator 84 (for example, +5 V of a high-current system, P +
P of 5V indicates a high electric power system. ) Is operational amplifier 5
1, the operational amplifier 7 and the light emitting diode 11.

Since the other configuration is the same as the configuration of the first embodiment, the same portions are denoted by the same reference numerals, and detailed description thereof will be omitted.

As described above, according to the third embodiment, the +
The operational amplifier 71 operates upon receiving 12V, and the operational amplifier 7
A periodic pulse is generated by a multivibrator including “1”, and the generated pulse is amplified by the transistor 77. Then, the voltage is converted from a weak electric system to a strong electric system via insulation by a transformer 78, and the voltage is reduced. The voltage is rectified by a diode 79, a diode 81, a capacitor 80, a capacitor 82, a capacitor 83, etc. Is converted to DC.

Then, the switching regulator 84 converts the pulse duty ratio from +12 V to P + 5 V of the high current system, and operates the operational amplifier 51, the operational amplifier 7, and the light emitting diode 11.

That is, +12 V of the weak electric system is converted to +5 V of the strong electric system by the insulated power supply using the multivibrator, so that a stabilized electric power system of the strong electric system can be obtained through the insulation of the weak electric system. Further, the operational amplifier 51, the operational amplifier 7, the light emitting diode 1
1, the breakdown voltage of these elements may be low.

Third Embodiment Next, a third embodiment of the voltage sensor for an electric vehicle according to the present invention will be described. FIG. 8 shows a voltage sensor for an electric vehicle according to the third embodiment for measuring individual voltages of batteries connected in series.

In FIG. 1, the case where the voltage sensor 1 is provided for the battery 2b has been described. However, actually, as shown in FIG. 8, each of the batteries 2a, 2b, 2c... Of the voltage sensors 1a, 1b, 1c... 1n are provided. Further, each of the voltage sensors 1a, 1b, 1c
.. 1n are individually provided with a stabilized power source 5 as shown in FIG.
(Not shown).

The reason why the stabilized power supply 5 is provided for each voltage sensor is as follows. If the voltage of one stabilized power supply 5 is divided and 12 V is supplied to each voltage sensor, for example, 288 V is supplied to the voltage sensor 1a, for example, and the withstand voltage of the voltage sensor 1a becomes a problem. It is.

According to such a configuration, each voltage sensor 1a, 1b, 1c... 1n can measure a single voltage of each battery corresponding to each voltage sensor.

Further, since each voltage sensor is small and inexpensive, it is most suitable as an electric vehicle voltage sensor for managing the voltage of each battery of a plurality of batteries connected in series.

<Embodiment 4> FIG. 9 is a circuit diagram of an embodiment 4 of an electric vehicle voltage sensor according to the present invention. The voltage sensor 1a shown in FIG. 9 includes a plurality of batteries 2a, 2b
... are connected in series to form a high-current battery 2
Of the battery (for example, the battery 2b). The high-power battery 2 constitutes a primary-side circuit power supply, and applies a high voltage to the motor to rotate the motor so that the electric vehicle runs.

The weak electric power supply 3 is, for example, a +12 V power supply, and supplies a voltage to the voltage sensor 1a when the voltage sensor 1a detects a terminal voltage, for example, when the ignition is turned on or during charging of the battery. . For this reason, the weak electric power source 3 has a switching element such as a switching transistor or a relay (not shown).

Next, in the voltage sensor 1a, a resistor 3a and a resistor 3b are connected in series to both ends of the battery 2b. The voltage supply control unit 86 receives the voltage from the weak electric power source 3 only when the battery is detected, and supplies the voltage of the strong electric power battery 2 b to the strong electric power stabilized power source 94 with this voltage. The voltage supply control unit 86 includes a first photocoupler 87, a resistor 90, a transistor 91, and the like.

The first photocoupler 87 includes a first light emitting diode 88 as a light emitting element and a first phototransistor 89 as a light receiving element. The first light emitting diode 88 forms an input side which is a primary side, and the first phototransistor 89 forms an output side which is a secondary side. The primary side and the secondary side are insulated. The cathode of the first light emitting diode 88 is grounded, and the anode of the first light emitting diode 88 is connected to the weak power source 3 via the resistor 90.

The first light emitting diode 88 emits light when the voltage of the weak power source 3 is supplied via the resistor 90, that is, when the terminal voltage of the battery 2b is detected. First
Of the first light emitting diode 8
The transistor 91 is operated by receiving the light of No. 8.

The emitter of the transistor 91 is connected to the positive electrode side of the battery 2b, and a resistor 92 is connected between the emitter and the base of the transistor 91. The base of the transistor 91 is connected to the collector of the first phototransistor 89 via the resistor 93, and the emitter of the first phototransistor 89 is connected to the negative electrode of the battery 2b.

The collector of the transistor 91 is connected to a power stabilizing power supply 94 for stabilizing the voltage from the battery 2b via the transistor 91. The strong current stabilizing power supply 94 supplies a stabilized voltage to the voltage frequency converter 95 and the anode of the second light emitting diode 97 in the second photocoupler 96.

The second photocoupler 96 comprises a second light emitting diode 97 as a light emitting element and a second photo transistor 98 as a light receiving element. The second light emitting diode 97 forms an input side which is a primary side, and the second phototransistor 98 forms an output side which is a secondary side. The primary side is a strong electric system, the secondary side is a weak electric system, and the strong electric system and the weak electric system are insulated.

The voltage frequency converter 95 receives the divided voltage of the resistors 3a and 3b, converts the divided voltage into a frequency corresponding to the voltage, and outputs the frequency to the cathode of the second light emitting diode 97.

The second light emitting diode 97 emits light or emits no light at an emission frequency corresponding to the cycle of the frequency output from the voltage frequency converter 95. Second phototransistor 9
8 receives the light of the second light emitting diode 97 and outputs a light receiving frequency corresponding to the light emitting frequency as a detection output corresponding to the terminal voltage of the battery. Second phototransistor 9
The voltage of the weak power supply 3 for operating the second phototransistor 98 is supplied to the collector 8.

The frequency output of the second phototransistor 98 is sent to a battery controller (not shown) and processed by the battery controller to measure the voltage of the battery alone. The emitter of the second phototransistor 98 is grounded.

Next, the fourth embodiment configured as described above will be described.
The operation of the voltage sensor will be described with reference to FIG. First,
When detecting the terminal voltage of the battery 2b, the weak electric power source 3 supplies the voltage to the resistor 90, and the voltage of the weak electric power source 3 is supplied to the first light emitting diode 88 via the resistor 90. One light emitting diode 88 emits light.

Then, the first phototransistor 89 operates by receiving the light of the first light-emitting diode 88, so that the first phototransistor 89 operates from the positive electrode side of the battery 2b through the resistors 92, 93 and the first phototransistor 89. A current flows to the negative electrode side of 2b.

Therefore, transistor 91 operates,
The voltage of the strong electric system of the battery 2b is supplied to the strong electric system stabilized power supply 94. The strong electric system stabilized power supply 94 converts the stabilized voltage to the voltage frequency converter 95, only when the voltage of the battery 2b is detected.
A second light emitting diode 97 is provided.

When the divided voltage of the resistors 3a and 3b is input to the voltage frequency converter 95, the voltage frequency converter 95 changes the divided voltage to a frequency corresponding to the voltage and outputs the second divided voltage. To the cathode of the light-emitting diode 97.

Then, the second light emitting diode 97 emits light or does not emit light at an emission frequency corresponding to the cycle of the frequency output from the voltage frequency converter 95, so that the second phototransistor 98 is connected to the second light emitting diode 97. 97, and outputs a light receiving frequency corresponding to the terminal voltage of the battery 2b. Then, a battery controller (not shown)
The frequency output from the voltage sensor 1a is processed to
Measure the terminal voltage at b.

As described above, according to the voltage sensor of the fourth embodiment, the voltage sensor 1a is configured by using the first and second photocouplers 87 and 96 having insulating properties. As compared with the conventional voltage sensor, it is possible to provide a voltage sensor which is smaller in size, inexpensive and has insulating properties.

Also, the weak electric power source 3 drives the strong electric power stabilized power source 94 only when the voltage of the battery 2b is detected.
Since the voltage-frequency converter 95 and the second light-emitting diode 97 are operated, the voltage-frequency converter is supplied from the strong electric-system stabilized power supply 94 which receives the power of the strong electric-system battery 2b, except at the time of detecting the voltage of the strong electric-system battery alone. 95 and the dark current flowing through the second photodiode 97 in the second photocoupler 96 can be eliminated. By preventing the dark current from flowing, the discharge of the high-power battery 2b can be prevented.

Further, since the voltage-frequency converter 95 is used, the output can be obtained at a frequency, so that the output can be reduced in noise and an accurate output can be obtained.

<Fifth Embodiment> Next, a fifth embodiment of the voltage sensor for an electric vehicle according to the present invention will be described. Three specific examples of the voltage sensor according to the fifth embodiment, that is, voltage sensors that measure the total voltage of a plurality of batteries connected in series will be described with reference to three examples.

(Embodiment 4) First, FIG. 10 shows a circuit configuration diagram of Embodiment 1 of a voltage sensor for measuring the total voltage of a plurality of batteries connected in series. In FIG. 10, a high-power battery 2 (for example, 288 V) is connected between a point P and a point N, and a resistor R is connected between the point P and the point N.
1, R2, R16, R3, R4, R12, and R15 are connected, and one end of the resistor R13 and the point N are grounded.

The voltage supply control unit 86 is connected to the point P,
The weak power supply 3 and the strong power stabilization power supply 94 are connected to the voltage supply control unit 86. Stabilized power supply 94
Stabilizes the voltage of the strong-current battery 2 of 288V,
The stable voltage of the high current system is supplied to the voltage frequency converter 95 and the anode of the second light emitting diode 97.

The connection point between the resistors R4 and R12 is connected to the non-inverting input terminal of the operational amplifier 51.
1 is directly connected to the inverting input terminal and the output terminal, and a capacitor 52 is connected between the power supply of the operational amplifier 51 and the ground to form a voltage follower circuit.

The resistor 53 is connected between the output terminal of the operational amplifier 51 and the inverting input terminal of the operational amplifier 7, and
One end of the resistor 4 is connected to the output terminal of the operational amplifier 51, and the other end of the resistor 54 is grounded.

Since the configuration of the circuit including the voltage frequency converter 95 and the second photocoupler 96 is substantially the same as the configuration shown in FIG. 9, the same portions are denoted by the same reference numerals and description thereof will be omitted. .

Next, the operation of the fourth embodiment thus configured will be described. First, when the weak electric power source 3 supplies the power to the voltage supply control unit 86 when detecting the total voltage of the strong electric battery, the voltage supply control unit 86 responds accordingly by detecting the point P at the time of detecting the total voltage of the strong electric battery. Is supplied to the strong electric system stabilizing power supply 94.

Then, the strong current stabilizing power supply 94 stabilizes the voltage (288 V) of the strong current battery 2 and supplies the strong current voltage directly to the operational amplifier 51, the voltage frequency converter 95, and the second photocoupler 96. The operational amplifier 5
1. Voltage frequency converter 95, second light emitting diode 97
Works. In this case, the operational amplifier 51, the voltage frequency converter 95, and the second light emitting diode 97 need to be able to withstand a high voltage. Further, the voltage of the high-current system is directly applied to the operational amplifier 51, the voltage-frequency converter 95, and the second light-emitting diode 9.
7 is not insulated.

Next, the voltage of the high-current system at the resistor R12 is input to the non-inverting input terminal of the operational amplifier 51, and the voltage of the operational amplifier 5
The voltage is converted from high impedance to low impedance by 1, and the output voltage of the operational amplifier 51 is input to the voltage frequency converter 95 via the resistor 53. Then, the voltage frequency converter 95 and the second photocoupler 96 operate as described in the operation of the fourth embodiment. That is, the second phototransistor 98 can output a frequency corresponding to the total voltage of the entire battery.

(Embodiment 5) FIG. 11 shows a circuit configuration diagram of Embodiment 5 of a voltage sensor for measuring the total voltage of a plurality of batteries connected in series. In the fifth embodiment, the fourth embodiment
And a DC-DC converter 55 is provided in place of the strong electric system stabilized power supply 94.

The weak electric power source 3 supplies the voltage to the DC-DC converter 55 when detecting the voltage of the whole battery. D
When detecting the voltage of the entire battery, the C-DC converter 55 converts +12 V of the weak electric power source 3 to +5 V or +5 of the strong electric system.
For example, a transformer for converting to 12 V is used to insulate the weak electric system from the strong electric system.

A capacitor 56 and a switching regulator 58 are connected to the output of the DC-DC converter 55. The output of the switching regulator 58 (for example, + 5V of the high-voltage system, P + 5V of P in FIG. 11 indicates that the system is a high-voltage system). ) Is the operational amplifier 51 and the voltage frequency converter 9
5. The light is supplied to the light emitting diode 97.

Since the rest of the configuration is the same as the configuration of the fourth embodiment, the same portions are denoted by the same reference numerals, and detailed description thereof will be omitted.

As described above, according to the fifth embodiment, the DC-DC
The converter 55 converts the weak electric system + 12V to the strong electric system +5.
Since the voltage is converted to V, it is possible to obtain a stabilized power supply of the strong electric system through the insulation of the weak electric system. Further, since the operational amplifier 51, the voltage frequency converter 95, and the light emitting diode 97 are operated by the converted high-voltage system voltage, the breakdown voltages of these elements may be low.

Furthermore, since the weak power supply 3 supplies the voltage to the DC / DC converter 55 only when the voltage of the entire battery is detected, the operational amplifier 51, the voltage frequency converter 95, and the light emitting diode 97 operate only when the voltage is detected. I do.
Therefore, current consumption can be reduced.

(Embodiment 6) FIG. 12 shows a circuit configuration diagram of Embodiment 6 of a voltage sensor for measuring the total voltage of a plurality of batteries connected in series. The sixth embodiment is characterized in that an insulated power supply 70 using a multivibrator is provided in place of the strong electric power stabilized power supply 94 of the fourth embodiment.

The weak electric power source 3 supplies the voltage to the insulated power source 70 when the voltage of the whole battery is detected. Insulated power supply 7
0 is +12 V of the weak electric system when the voltage of the entire battery is detected.
Is converted to + 5V or + 12V of the strong electric system, and insulates the weak electric system from the strong electric system. The operational amplifier 71 is supplied with +12 V of a weak current system, a capacitor 72 is connected between the inverted input terminal of the operational amplifier 71 and the ground, and a resistor 7 is connected between the inverted input terminal and the output terminal of the operational amplifier 71.
3 are connected.

A resistor 74 is connected between the non-inverting input terminal of the operational amplifier 71 and the ground, and a resistor 75 is connected between the non-inverting input terminal and the output terminal of the operational amplifier 71 to form a multivibrator. I have.

The output of the operational amplifier 71 is connected to the base of the transistor 77 via the resistor 76, and the collector is +1
2V, and the emitter is connected to one end of the primary winding of the transformer 78. The other end of the primary winding of the transformer 78 is grounded. The transformer 78 insulates the primary side weak current system from the secondary side strong current system. One end of the secondary winding of the transformer 78 is connected to the anode of the diode 79 and the cathode of the diode 81.
9 and the other end of the secondary winding between the capacitor 8
0 is connected.

A capacitor 82 is connected between the other end of the secondary winding and the anode of the diode 81.
One end of 3 is connected to the cathode of diode 79. The other end of the capacitor 83, the anode of the diode 81, and one end of the capacitor 82 are grounded.

A switching regulator 84 is connected to the cathode of the diode 79. The output of the switching regulator 84 (for example, +5 V of a high-current system, P
P of +5 V indicates that it is a strong electric system. ) Are supplied to the operational amplifier 51, the voltage frequency converter 95, and the light emitting diode 97.

Since the rest of the configuration is the same as the configuration of the fourth embodiment, the same portions are denoted by the same reference numerals, and detailed description thereof will be omitted.

As described above, according to the sixth embodiment, at the time of detecting the voltage of the entire battery, the operational amplifier 71 operates by receiving +12 V from the weak electric power source 3, and the multivibrator including the operational amplifier 71 generates a periodic pulse. The generated pulse is amplified by the transistor 77. Then, the voltage is reduced from the weak electric system to the strong electric system via insulation by the transformer 78, and the voltage is reduced.
Rectified by capacitors 82, 83, etc.
It is converted from AC to DC.

Then, the switching regulator 84 converts the pulse duty ratio from +12 V to P + 5 V of the high current system, and operates the operational amplifier 51, the voltage frequency converter 95, and the light emitting diode 97.

That is, since +12 V of the weak electric system is converted to +5 V of the strong electric system by the insulating type power supply using the multivibrator, a stabilized electric power system of the strong electric system can be obtained through the insulation of the weak electric system. Further, since the operational amplifier 51, the voltage frequency converter 95, and the light emitting diode 97 are operated by the converted high-voltage system voltage, the breakdown voltages of these elements may be low.

Further, since the weak power supply 3 supplies the voltage to the insulated power supply 70 including the multivibrator only when the voltage of the whole battery is detected, the operational amplifier 51, the voltage frequency converter 95, the light emitting diode 9
7 operates. Therefore, current consumption can be reduced.

[0138]

According to the first aspect of the present invention, when the voltage of the high-power battery power supply stabilized by the stabilized power supply is supplied to the light emitting element, the light emitting element emits light, and the light of the light emitting element is transmitted to the first light emitting element.
And the second light receiving element receives light. The differential amplifier circuit amplifies the voltage of the battery power supply and the feedback voltage fed back from the first light receiving element, and controls the light emission output of the light emitting element based on the amplified voltage. At this time, the second light receiving element also performs the same operation as the first light receiving element.
A voltage based on a light receiving output input from both ends of the second light receiving element is integrated, and the integrated voltage is output as a detection voltage corresponding to a voltage of a high-power battery power supply. Further, since the strong current system and the weak current system are insulated from each other, it is possible to provide a small-sized and inexpensive voltage sensor having an insulating property.

According to the second aspect of the present invention, since the voltage sensor is provided for each battery power source, it is possible to measure a single voltage of each battery power source of the plurality of battery power sources.

According to the third aspect of the present invention, since the integration circuit outputs a detection voltage corresponding to the voltage of a plurality of high-power system battery power supplies, a plurality of high-power systems connected in series by one voltage sensor. It is possible to detect the total voltage of the battery power supply, and to provide a compact and inexpensive voltage sensor.

According to the fourth aspect of the present invention, the stabilized power supply stabilizes the total voltage of the plurality of high-power battery power supplies and supplies the stabilized voltage to the differential operation amplifier circuit and the light emitting element. Can operate the differential operation amplifier circuit and the light emitting element.

According to the fifth aspect of the present invention, the stabilized power supply converts the voltage of the weak electric power supply to the voltage of the high electric power supply through insulation, and compares the converted voltage of the strong electric power supply with the difference. Since it is supplied to the operation amplifier circuit and the light-emitting element, it insulates the high-current system from the low-current system, and does not receive the voltage from a plurality of battery power supplies of the high-current system. Can work,
In addition, the breakdown voltage of the differential operation amplifier circuit and the light emitting element can be reduced.

According to the sixth aspect of the present invention, the voltage-frequency converter operated by the voltage of the high-voltage stabilized power supply converts the terminal voltage of the high-voltage battery to a frequency corresponding to the voltage, and the insulating section is connected to the input side. The voltage converted by the voltage-frequency converter while the voltage of the strong current stabilized power supply is supplied, the voltage of the weak electric power supply is supplied to the output side, and the input side and the output side are insulated is output to the terminal of the strong current system battery. Since the detection signal is output as a detection output corresponding to the voltage, it is possible to provide a small-sized, inexpensive and insulated voltage sensor.

According to the seventh aspect of the present invention, since the voltage sensor is provided for each of the plurality of high-voltage batteries, a frequency corresponding to the single voltage of the high-voltage battery is output for each high-voltage battery. it can.

According to the eighth aspect of the present invention, the voltage supply control section includes:
When the terminal voltage of the high-power battery is detected, it operates with the voltage of the low-power battery and supplies the terminal voltage of the high-power battery to the high-power stabilized power supply. At the time of detection, the voltage frequency converter and the insulating unit are operated. For this reason, it is possible to eliminate the dark current flowing at times other than the time of detecting the voltage of the high-current battery,
As a result, it is possible to prevent discharge of the high-power battery.

According to the ninth aspect of the present invention, since the insulating section outputs the frequency converted by the voltage frequency converter as a detection output corresponding to the total voltage of a plurality of high-voltage batteries, only one voltage sensor is required. Further, it is possible to provide a compact and inexpensive voltage sensor.

According to the tenth aspect of the present invention, it is possible to eliminate the dark current flowing at times other than the time of detecting the voltage of the high-voltage battery, thereby preventing the discharge of the high-voltage battery.

According to the eleventh aspect of the present invention, the stabilized power supply stabilizes the total voltage of the plurality of high-voltage batteries and supplies the stabilized voltage to the input side of the voltage frequency converter and the insulating section. The power supply of the system can operate the input side of the voltage-frequency converter and the insulating unit.

According to the twelfth aspect of the present invention, the stabilized power supply converts the voltage of the weak electric power supply to the voltage of the strong electric power supply through insulation, and converts the converted voltage of the strong electric power supply to a voltage frequency converter and an insulating unit. Supply to the input side of the power supply, insulates between the high-current system and the low-current system, and operates the voltage-frequency converter and the input side of the insulation unit with the power supply of the high-current system without receiving the voltage from multiple batteries. And the withstand voltage on the input side of the voltage frequency converter and the insulating portion can be low.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of Embodiment 1 of a voltage sensor for an electric vehicle according to the present invention.

FIG. 2 is a circuit configuration diagram of a strong electric system and a weak electric system in the electric vehicle.

FIG. 3 is a configuration diagram illustrating a voltage monitoring device including a voltage sensor and a battery controller.

FIG. 4 is a diagram showing an electric vehicle voltage sensor according to a second embodiment for measuring the total voltage of batteries connected in series.

FIG. 5 is a circuit configuration diagram illustrating a first embodiment of a voltage sensor that measures a total voltage of a plurality of batteries connected in series.

FIG. 6 is a circuit configuration diagram showing a second embodiment of a voltage sensor for measuring the total voltage of a plurality of batteries connected in series.

FIG. 7 is a circuit configuration diagram showing a third embodiment of a voltage sensor for measuring the total voltage of a plurality of batteries connected in series.

FIG. 8 is a diagram showing an electric vehicle voltage sensor according to a third embodiment for measuring individual voltages of batteries connected in series.

FIG. 9 is a circuit configuration diagram of an electric vehicle voltage sensor according to a fourth embodiment of the present invention.

FIG. 10 is a circuit configuration diagram showing a fourth embodiment of a voltage sensor for measuring the total voltage of a plurality of batteries connected in series.

FIG. 11 is a circuit configuration diagram showing a fifth embodiment of a voltage sensor for measuring the total voltage of a plurality of batteries connected in series.

FIG. 12 is a circuit diagram showing a sixth embodiment of a voltage sensor for measuring the total voltage of a plurality of batteries connected in series.

FIG. 13 is a diagram showing a configuration of a conventional voltage sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1,101 Voltage sensor 2 High-current battery 2a-2n battery 3 Low-current power source 3a, 3b, 19 Voltage dividing resistor 5, 5a Stabilized power source 7, 17 Operational amplifier 9 Photocoupler IC 11 Light emitting diode 13, 15 Photodiode 21 Capacitor 31 Motor controller driver 33 Motor 35 Current sensor 37 Battery controller 39 Light electric system equipment 41 Light electric system battery 43 Battery cooling fan 45 Charger 47 Motor controller 49 Meter 55 DC-DC converter 71 Multivibrator 86 Voltage supply control unit 87 First photo Coupler 91 Transistor 94 Strong electric power stabilized power supply 95 Voltage frequency converter 96 Second photocoupler 103 Magnetic core 115 Hall element 117 Current amplifier

Claims (12)

[Claims] 1. A stabilized power supply for stabilizing a voltage of a high-power battery power supply, a light emitting element that emits light by the voltage of the stabilized power supply, a first light receiving element and a second light receiving element that receive light from the light emitting element. And a light-emitting element driven by the voltage of the stabilized power supply, amplifying a voltage of the battery power supply and a feedback voltage fed back from the first light-receiving element, and emitting light of the light-emitting element based on the amplified voltage. A differential amplifier circuit to be controlled; a drive circuit driven by a voltage of a battery power source of a weak current system; integrating a voltage based on a light receiving output input from both ends of the second light receiving element; and integrating the integrated voltage with the battery of the strong current system. A voltage sensor for an electric vehicle, comprising: an integration circuit that outputs a detection voltage corresponding to a voltage of a power supply. 2. A plurality of voltage detectors provided in one-to-one correspondence with each of a plurality of series-connected battery power supplies of a high-power system and detecting a terminal voltage of the battery power supply, Each of the voltage detectors includes a stabilized power supply for stabilizing the voltage of the high-power battery power supply, a light emitting element that emits light by the voltage of the stabilized power supply, a first light receiving element that receives light from the light emitting element, and A second light receiving element, driven by the voltage of the stabilized power supply, amplifies a voltage of the battery power supply and a feedback voltage fed back from the first light receiving element, and emits light of the light emitting element based on the amplified voltage. A differential amplifier circuit for controlling an output, driven by a voltage of a battery power source of a weak electric system, integrating a voltage based on a light receiving output inputted from both ends of the second light receiving element, and integrating the integrated voltage into the strong electric system. Battery A voltage sensor for an electric vehicle, comprising: an integration circuit that outputs a detection voltage corresponding to a voltage of a power supply. 3. A voltage sensor for an electric vehicle which detects a total voltage of a plurality of battery power supplies of a series of high-power systems connected in series, comprising: a stabilized power supply; and a light emitting element which emits light by the voltage of the stabilized power supply. A first light-receiving element and a second light-receiving element that receive light from the light-emitting element; a light-receiving element driven by a voltage of the stabilized power supply; A differential amplifier circuit for amplifying the feedback voltage fed back from the amplifier and controlling the light emitting output of the light emitting element based on the amplified voltage; An integration circuit that integrates a voltage based on a light receiving output input from the power supply and outputs the integrated voltage as a detection voltage corresponding to the voltage of the plurality of high-power battery power supplies. for Pressure sensor. 4. The stabilized power supply stabilizes the total voltage of the plurality of high-power battery power supplies and supplies the stabilized voltage to the differential operation amplifier circuit and the light emitting element. The voltage sensor for an electric vehicle according to claim 3. 5. The stabilized power supply converts a voltage of the battery power supply of the weak current system into a voltage of the battery power supply of the high current system via insulation, and converts the converted voltage of the battery power supply of the high current system into the differential operation. 4. The voltage sensor for an electric vehicle according to claim 3, wherein the voltage is supplied to an amplifier circuit and the light emitting element. 6. A strong electric power stabilizing power supply for stabilizing a terminal voltage of the strong electric power battery, and operated by the voltage of the strong electric power stabilized power supply, and converting the terminal voltage of the strong electric power battery into a frequency corresponding to the voltage. A voltage frequency converter that supplies the voltage of the strong electric power stabilized power supply to the input side, the voltage of the weak electric power supply to the output side, and insulates the input side and the output side. An insulation unit that outputs the frequency converted by the converter as a detection output corresponding to the terminal voltage of the high-power battery, and a voltage sensor for an electric vehicle. 7. A plurality of voltage detectors provided in one-to-one correspondence with each of the plurality of high-power batteries connected in series, wherein each of the voltage detectors includes a terminal of the high-power battery. A strong current stabilizing power supply for stabilizing the voltage, a voltage frequency converter that operates by the voltage of the strong current stabilizing power supply, and converts a terminal voltage of the strong current battery into a frequency corresponding to the voltage; The voltage of the strong electric power stabilized power supply is supplied, the voltage of the weak electric power supply is supplied to the output side, and the frequency converted by the voltage frequency converter in a state where the input side and the output side are insulated, A voltage sensor for an electric vehicle, comprising: an insulating unit that outputs a detection output corresponding to a terminal voltage of a high-power battery. 8. When detecting the terminal voltage of the high-power battery, when the low-power power supply operates, the low-power power supply operates with the voltage of the low-power power supply, and the terminal voltage of the high-power battery is supplied to the high-power stabilized power supply. 8. The voltage sensor for an electric vehicle according to claim 6, further comprising a voltage supply control unit for supplying the voltage. 9. A voltage sensor for an electric vehicle for detecting a total voltage of a plurality of high-power batteries connected in series, comprising: a stabilized power supply; A voltage frequency converter for converting the total voltage of the high-voltage battery into a frequency corresponding to the voltage, a voltage of the stabilized power supply being supplied to an input side, a voltage of a weak power supply being supplied to an output side, and And an insulating unit that outputs a frequency converted by the voltage frequency converter in a state where the output side is insulated from the output side as a detection output corresponding to a total voltage of the plurality of high-voltage batteries. Voltage sensor for electric vehicles. 10. When detecting the total voltage of the plurality of high-voltage batteries, when the low-voltage power supply operates, the low-voltage power supply operates with the voltage of the low-voltage power supply, and calculates the total voltage of the plurality of high-voltage batteries. The voltage sensor for an electric vehicle according to claim 9, further comprising a voltage supply control unit configured to supply the voltage to the stabilized power supply. 11. The stabilized power supply stabilizes a total voltage of the plurality of high-voltage batteries and supplies a stabilized voltage to an input side of the voltage frequency converter and the insulating unit. The voltage sensor for an electric vehicle according to claim 9. 12. The stabilized power supply converts a voltage of the weak electric power supply into a voltage of a strong electric power supply through insulation, and converts the converted voltage of the strong electric power supply to the voltage frequency converter and the insulating unit. The voltage sensor for an electric vehicle according to claim 9, wherein the voltage is supplied to an input side of the electric vehicle.