1063results about "Very high resistance measurements" patented technology

An insulation resistance determining system (50) comprises an insulation resistance determining portion configured by connecting a coupling capacitor (52), a detection resistor (54), and a pulse oscillating circuit (56) in series with a common mode potential measuring point (30), and an insulation resistance determining portion having a filter (58) which processes an AC signal (v_x) at a junction between the coupling capacitor (52) and the detection resistor (54), an amplifier (60), a wave-peak value detection circuit (62), and a controller (70). The controller (70) has functions for detecting a drop in insulation resistance in response to an output of the wave-peak value detection circuit (62); for requesting an HVCPU (40) to change the common mode potential so as to determine a failure of the insulation resistance determining portion; and for determining a failure of the insulation resistance determining portion from an output change of the wave-peak value determining circuit (62) between before and after the common mode potential change.

The vehicular insulation resistance detection apparatus includes a cyclic signal generating unit that generates a cyclic signal, a first resistor that has one end to which the cyclic signal is applied, a first capacitor that has one end connected to the other end of the first resistor and the other end connected to a high-voltage circuit, a second capacitor that has one end connected to the other end of the first resistor, a second resistor that has one end connected to the other end of the second capacitor and the other end connected to a low-voltage ground that is a circuit ground of a low-voltage circuit, a series circuit that includes a diode and a third resistor connected in series, and is connected in parallel with the second capacitor, this diode having a forward direction coincident with a direction from the other end of the second capacitor to the one end of the second capacitor, a voltage detection unit that detects a voltage between the low-voltage ground and the other end of the second capacitor as a detection signal, and an insulation resistance detection unit that detects a resistance value of an insulation resistance based on an amplitude of the detection signal.

A device for detecting the insulation resistance of a high-voltage battery system of a motor vehicle that includes a high-voltage battery and a high-voltage component which is operatively connected to terminals of the high-voltage battery via converters. The device includes a reference resistor operatively connected to the terminals of the high-voltage battery via switches, with a voltage measurement device configured to detect the voltage present between each respective terminal and a reference potential of the vehicle; a voltage measurement device configured to measure the voltage between the terminals; and a coupling circuit configured to monitor the high-voltage component when the converters are open.

The present invention is a high-sensitivity insulation resistance detection method and circuit for an ungrounded DC power supply systems. When the ratio of the voltage of the positive bus to that of the negative bus exceeds a preset range, the DC current is injected into the ungrounded DC power supply systems. DC power supply systems have essentially some grounded stray and external capacitors, so some of the injected DC current will flow into the grounded capacitor, increasing the voltage of the fault bus and the leakage current. The proposed method increases the leakage current by the injection of DC current, so the current sensor can detect the leakage current from which the insulation resistance can be calculated. The DC current injection method can significantly improve the detection of ground insulation faults in ungrounded DC power supply systems.

The invention relates to an automobile insulation resistance detection circuit and method, and the circuit comprises a negative bleeder resistor, a positive bleeder resistor, a first sampling resistor, a second sampling resistor, a third sampling resistor, a fourth sampling resistor, a fifth sampling resistor, a sixth sampling resistor, a negative switch, and a positive switch. One end of the negative bleeder resistor is connected with the negative electrode of a detected battery, and the other end of the negative bleeder resistor is grounded. One end of the positive bleeder resistor is connected with the positive electrode of the detected battery, and the other end is grounded. One end of the first sampling resistor is connected with the negative electrode, and the other end of the sampling resistor is connected with one end of the negative switch. The other end of the negative switch is connected with one end of the second sampling resistor, and the other end of the second sampling resistor is grounded. One end of the third sampling resistor is connected with the positive electrode, and the other end of the third sampling resistor is connected with one end of the positive switch. The other end of the positive switch is connected with one end of the fourth sampling resistor, and the other end of the fourth sampling resistor is grounded. One end of the fifth sampling resistor is connected with the positive electrode, and the other end of the fifth sampling resistor is connected with one end of the sixth sampling resistor. The other end of the sixth sampling resistor is connected with the negative electrode. According to the scheme of the invention, the circuit can improve the detection precision of insulation resistance.

An object is to detect an insulation failure of a DC circuit with high sensitivity and in safety by means of a simple detection circuit. An insulation resistance measurement device of this invention is a device for measuring an insulation resistance to ground of a DC source circuit and is provided with connection terminals for connections to a positive electrode and a negative electrode of a series power supply, switch elements connected between the connection terminals and the ground potential and configured to switch connections between the connection terminals and the ground potential, resistive elements connected through the switch elements between the connection terminals, respectively, and the ground potential, and a voltage detection unit for detecting voltage drops in the resistive elements.

Battery insulation resistance measurement methods, insulation resistance measurement methods, insulation resistance determination apparatuses, and articles of manufacture are described. According to one aspect, a battery insulation resistance measurement method includes determining a voltage of a battery, determining a voltage of a first terminal of the battery with respect to a ground reference, determining a voltage of a second terminal of the battery with respect to the ground reference, and using the voltages of the battery, the first terminal and the second terminal, determining an insulation resistance of the battery with respect to the ground reference.

A motor drive device includes: a converter; a power supply; a plurality of inverter units configured to convert DC to AC to drive a plurality of motors by upper arm switching elements connected between a capacitor and motor coils and lower arm switching elements connected between the capacitor and motor coils; a second switch configured to connect the capacitor to the earth; a current detector configured to measure current flowing between the capacitor and the earth; a voltage detector configured to measure the voltage across the capacitor; and, an insulation resistance detector configured to detect insulation resistance of the multiple motors based on the current and voltage measured in a condition that the switching element to which the motor coil to be measured is connected is turned on and the switching elements to which a motor coil other than the target for measurement is connected are turned off.

An insulation resistance decrease detector for an industrial vehicle is disclosed. The detector includes a coupling capacitor, a sensing resistor, an AC voltage applying section having a first terminal and a second terminal, a voltage detecting section, and a determining section. The AC voltage applying section applies an AC voltage of a predetermined frequency to the vehicle body through the sensing resistor and the coupling capacitor. The voltage detecting section detects the voltage at a node between the sensing resistor and the coupling capacitor. The determining section determines that a resistance value of the insulation resistor has decreased when the level of voltage detected by the voltage detecting section becomes less than or equal to a predetermined level.

The invention discloses a novel insulation detection device for electric automobiles.The novel insulation detection device for electric automobiles comprises a low-frequency pulse signal generator, a high-frequency pulse signal generator, a first operational amplifier, a second operational amplifier, a third operational amplifier, a one-out-of-two selective switch, a sampling circuit and a processor unit.The sampling circuit comprises a first branch circuit, a second branch circuit and a fifth resistor, wherein the first branch circuit is formed by connecting a first resistor and a second resistor in series, and the second branch circuit is formed by connecting a third resistor and a fourth resistor in series.An input end of the first operational amplifier is connected to the positive pole or negative pole of a high-voltage battery through the selective switch.An input end of the second operational amplifier is connected to the parallel connection point of the first branch circuit and the second branch circuit.An input end of the third operational amplifier is connected to the connection point of the first resistor and the second resistor.The novel insulation detection device for electric automobiles widens the range of insulation detection of electric automobiles and improves the accuracy of insulation detection of electric automobiles.

The embodiment of the invention provides an insulation resistance detection circuit and method. The insulation resistance detection circuit provided by the embodiment of the invention comprises a battery, a first branch, a second branch, a third branch and a fourth branch, wherein the anode of the battery is connected with the first end of the first branch, a first voltage output point is arranged in the first branch, a first switch is arranged in the second branch, the first end of the second branch is connected with the first end of the first branch, the second end of the first branch and the second end of the second branch are both grounded, the cathode of the battery is connected with the first end of the third branch, a second voltage output point is arranged in the third branch, a second switch is arranged in the fourth branch, the first end of the fourth branch is connected with the first end of the third branch, and the second end of the third branch and the second end of the fourth branch are both grounded. According to the technical scheme, the detection range of the insulation resistance is expanded, and the detection efficiency of the insulation resistance is improved.

The invention discloses a power storage battery system insulation resistor detection circuit and detecting method. The power storage battery system insulation resistance detection circuit comprises afirst discharging resistor, a second discharging resistor, a first sampling resistor, a second sampling resistor, a third sampling resistor, a fourth sampling resistor, a detecting starting switch, afirst controlling switch, a second controlling switch, a third controlling switch and a fourth controlling switch; one end of the first discharging resistor is connected with a positive electrode of adetected battery, the other end of the first discharging resistor is connected with one end of the first controlling switch, and the other end of the first controlling switch is grounded; one end ofthe second discharging resistor is connected with a negative electrode of the detected battery, the other end of the second discharging resistor is connected with one end of the second controlling switch, and the other end of the second controlling switch is grounded. By means of the power storage battery system insulation resistor detection circuit and detecting method, the detection precision ofan insulation resistor is improved, and artificial increasing of leakage current of the system is avoided.

Provided is an insulation resistance measurement circuit including: a source resistance unit including a first source resistance unit connected to a positive terminal of an insulation resistance measurement battery and a second source resistance unit connected to a negative terminal of the insulation resistance measurement battery and the first source resistance unit; a voltage sensing unit including a first operational amplifier sensing the voltage of the first source resistance unit, as a first voltage, and the voltage of the second source resistance unit, as a second voltage; a leakage current interrupting unit including a first switch connected to the positive terminal of the insulation resistance measurement battery and the first source resistance unit and a second switch connected to the negative terminal of the insulation resistance measurement battery and the second source resistance unit; a measurement circuit testing unit including a third switch connected to the first operational amplifier and a first voltage source and a fourth switch connected to the second operational amplifier and a second voltage source; and an insulation resistance measurement unit measuring insulation resistance of the insulation resistance measurement battery through the first and second voltages.

The invention provides a method for testing the insulation resistance of a vehicle body, comprising the following steps: (1) generating a low-frequency AC signal and injecting the low-frequency AC signal into the vehicle body; (2) obtaining U through a first-level measurement circuit _{9_30} ; _9‑30 The average value in one cycle reflects the unbalanced condition of the positive and negative poles to the body resistance; the variation dU in half a cycle _{9_30} Participate in the calculation of the resistance value of the second-level measurement as the fluctuation parameter of the bus voltage; (3) obtain the AC voltage amplitude U through the second-level measurement circuit _{9_25} , a single insulation resistance R = F (U _{9_25} )*W, W is the weight, W=f(dU _{9_30} ); (4) Take the average value of each measurement to obtain the vehicle body insulation resistance Ravr=(w1*R1+w2*R2+.....Wn*Rn)/(w1+w2+....Wn). On the basis of the original low-frequency signal injection method, the present invention correlates the weight of the weighted filter when calculating the insulation resistance with the variation of the DC bus voltage fluctuation, the weight is small when the bus voltage fluctuates greatly, and the weight is large when the bus voltage fluctuates small, thus Make the test results tend to be stable and reliable.

The invention discloses an insulation resistance detection circuit and an insulation resistance detection method. The insulation resistance detection circuit comprises a positive busbar-to-earth voltage sampling circuit, which is used for sampling positive busbar-to-earth voltage; a positive busbar-to-earth voltage amplifying circuit, which is used for amplifying the sampled positive busbar-to-earth voltage, and comprises a first primary amplifying circuit and a first secondary amplifying circuit; a negative busbar-to-earth voltage sampling circuit, which is used for sampling negative busbar-to-earth voltage; a negative busbar-to-earth voltage amplifying circuit, which is used for amplifying the sampled negative busbar-to-earth voltage, and comprises a second primary amplifying circuit and a second secondary amplifying circuit; and a state switching circuit, which is used to switch connection between a positive busbar and a grounding point, connection between a negative busbar and the grounding point, and connection between earth and the grounding point to enable the insulation resistance detection circuit to be in different working states.

A method for measuring and calculating the isolation resistance of a battery pack is provided, the method being invulnerable to changes in the bus voltage that may take place between measurements.

The invention relates to an insulation impedance detection method for an electric automobile, and directly calculating the insulation resistance value of the positive and negative poles of the power battery of the electric vehicle on the vehicle body. The original detection circuit is connected with a resistor between a positive bus and a negative bus of the power battery pack, the insulation performance of the vehicle body is reduced by the access of the detection device, and the self-discharge rate of the battery can be increased.; a high-voltage isolating switch is adopted for controlling the positive and negative bus ends of the power battery, the detection resistor is not introduced when the insulation detection is not carried out, and adverse effects on the vehicle body are avoided.The electric automobile insulation impedance detection method is simple to operate and can accurately and effectively detect the insulation resistance.

This application discloses an insulation resistance detection circuit and detection method of a photovoltaic inverter, and the photovoltaic inverter. The detection circuit is composed of a first switch, a second switch, a first detection resistor and a second detection resistor. The first switch is connected in series with the first detection resistor to form a first branch; and a first end of the first branch is connected to a positive bus of a photovoltaic inverter and a second end of the first branch is connected to a ground wire. The second switch is connected in series with the second detection resistor to form a second branch; and a first end of the second branch is connected to a negative bus of the photovoltaic inverter and a second end of the second branch is connected to a ground wire. According to the detection circuit, the total ground insulation resistance of the photovoltaic array can be measured precisely in a full input voltage range. The detection circuit and detection method can be applied to any inverter with the any number of paths of inputs; and no additional device is needed for a multi-path series string input.

The present invention discloses an injection period adaptive strategy-based insulation resistance detection device and a method. The insulation resistance exists between a locomotive chassis and a locomotive power supply system. The detection device comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a sampling resistor, a signal injection circuit, a voltage signal acquisition circuit and a microcontroller. The voltage signal acquisition circuit is used for acquiring the voltage shared by the sampling resistor. The microcontroller is used for calculating the value of the insulation resistance. The detection method is provided for automatically adjusting the insulation resistance of an injection period. For the complex and changeable circuit structure of a high-voltage system, the injection period of a signal is automatically adjusted, so that the influence of the ground capacitance on the detection of the insulation resistance is eliminated. The real-time detection accuracy of the insulation resistance is improved. Meanwhile, the insulation resistance is effectively detected under the condition that the insulation of the positive electrode and the insulation of the negative electrode of the DC system are equivalently decreased.