Unlock instant, AI-driven research and patent intelligence for your innovation.

A high-precision multi-channel common ground DC power supply insulation resistance detection circuit and method

A DC power supply and insulation resistance technology, applied in the direction of measuring resistance/reactance/impedance, measuring devices, measuring electrical variables, etc., can solve the problem of increased circuit complexity and processor calculations, increased hardware circuit implementation costs, excessive resources, etc. question

Active Publication Date: 2017-04-12
SHANGHAI CHINT POWER SYST
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When the short-circuit current of the input DC source is large or the input has a large energy storage capacitor, the short-circuit switch in the circuit is very easy to damage
[0006] The above schemes are for judging whether the insulation resistance of the system exceeds the standard by constructing different circuit equations and obtaining each unknown insulation resistance separately. For the case of N input DC sources, N identical circuits are also required. To solve 2N unknown resistor values, even if one pole of the power supply is shared, it is necessary to solve N+1 unknown resistors, which will greatly increase the circuit complexity and the calculation amount of the processor, thereby increasing the hardware circuit implementation cost and occupying Excessive processor resources reduce system response speed

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A high-precision multi-channel common ground DC power supply insulation resistance detection circuit and method
  • A high-precision multi-channel common ground DC power supply insulation resistance detection circuit and method
  • A high-precision multi-channel common ground DC power supply insulation resistance detection circuit and method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Such as Figure 4 As shown, a multi-channel input DC power supply insulation impedance detection circuit disclosed in this embodiment includes m-channel DC power supplies, and their output voltages are V 1 , V 2 ,...,V m , the m-channel DC power supply is connected to the common negative pole, and the insulation resistance of the positive pole of each DC power supply to the ground is R p1 , R p2 ,...,R pm , the voltage across each insulation resistance is V p1 , V p2 ,...,V pm , resistor R n For the negative pole of the DC power supply to the ground, a series resistor R is connected in parallel between the negative pole of the DC power supply and the ground. 0 and the first switch S. The first switch S is a manual switch or a controllable switch. Resistance R 0 It is a single resistor composed of one resistor, or an equivalent resistor composed of at least two resistors connected in series or in parallel.

[0038] The method for detecting the insulation resi...

Embodiment 2

[0063] In analog circuits, the differential resistance sampling method is mostly used, such as Figure 5 As shown, including resistor R0 and resistor R1, its input signal is Vin. The smaller the input voltage Vin is, the larger the sampling error is due to parameters such as resistance precision and offset current of the operational amplifier. Therefore, in a DC system with a wide input voltage range, if the test circuit in Embodiment 1 is used, if Rn is much smaller than Rp, Vn will be small, and the voltage sampling error will be large, resulting in inaccurate insulation resistance detection.

[0064] In order to solve the situation of large insulation resistance detection error caused by inaccurate voltage sampling, the Figure 4 On the basis of , this embodiment makes design improvements, such as Figure 6 As shown, diodes D1, D2...Dm, resistor Ra and second switch Sa are added. The resistance value of the resistor Ra is equivalent to that of the resistor R0. When the s...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a multi-path input direct-current power supply insulation resistance detection circuit comprising m direct-current power supplies which are connected in a common negative pole mode or in a common positive pole mode. The circuit is characterized in that a resistor R0 and a switch which are connected in series are connected in parallel between the negative pole of the direct-current power supplies and the ground if the m direct-current power supplies are connected in a common negative pole mode; and the resistor R0 and the switch which are connected in series are connected in parallel between the positive pole of the direct-current power supplies and the ground if the m direct-current power supplies are connected in a common positive pole mode. The other technical scheme of the invention provides a multi-path input direct-current power supply insulation resistance detection method. The invention provides a simple and practical insulation resistance detection and calculation method for multiple-input direct-current power electronic systems with a common negative (positive) pole and has the advantages of simple hardware circuit, low software computation load and the like.

Description

technical field [0001] The invention relates to a multi-channel input DC power supply insulation impedance detection circuit and a detection method thereof, which are applied to a DC power supply system, and particularly relate to the field of photovoltaic power generation and battery application devices. Background technique [0002] In high-voltage DC power supply systems, such as photovoltaic power generation systems and electric vehicle power supply systems, in order to ensure the safety of operators, the DC system needs to have sufficient insulation. For example, according to the German VDE0126 requirements formulated for photovoltaic inverters, the DC power system needs to detect the insulation resistance. When the insulation resistance is less than the specified value, the inverter is not allowed to connect to the grid for operation. [0003] At present, the insulation resistance of photovoltaic inverters to the ground usually adopts a detection method based on the pr...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): G01R27/02
Inventor 张玉林朱国忠张俊
Owner SHANGHAI CHINT POWER SYST