CN2630860Y

CN2630860Y - DC system insulating monitoring instrument

Info

Publication number: CN2630860Y
Application number: CN 03212159
Authority: CN
Inventors: 王良润; 吴新军; 官红子
Original assignee: KEXIN Co ANSHAN SCIENCE-TECHNOLOGY UNIV
Current assignee: KEXIN Co ANSHAN SCIENCE-TECHNOLOGY UNIV
Priority date: 2003-03-26
Filing date: 2003-03-26
Publication date: 2004-08-04
Anticipated expiration: 2013-03-26

Abstract

The utility model discloses a direct current insulation monitor, which adopts a high precision leakage current sensor and a microcomputer control technique. The utility model also adopts a man machine interface of Chinese character on LCD to make it direct and convenient to know the system running insulated state. The direct current insulation monitor comprises: a control and storage circuit unit of the microprocessor, a keyboard-display unit, a bus extension, data collection, conversion, processing unit and a power supply. The utility model can be applied in one section of bus in the direct current system, and also can be used to monitor two sections of independent direct current bus system. The standard configuration of the monitor is I section bus 1-32 circuits, II section bus 1-32 circuits and can also be adjusted based on the actual situation of users. The system has date and clock display which can be real-time modified by the users. The monitor is furnished with RS-422 and RS-485 interface which can transfer the device running information to the host computer by a consistent communication protocol for the centralized supervision of the system.

Description

Straight-flow system insulating monitoring instrument

Technical field the utility model relates to the electrical system monitoring device, especially a kind of monitoring instrument of straight-flow system state of insulation.

In the DC earthing pick-up unit that background technology is moved at present, be mostly to be undertaken that ground connection detects by the threshold value of the balance resistance bridge of adjusting in electric system.There are shortcomings such as setting valve is inaccurate, insensitive, error big, ground voltage (stake resistance) can't be measured in this detection mode; The pick-up unit that some manufacturer production is also arranged is by adding AC signal on bus or branch road, detect the output valve of the current transformer of each branch road, and the judgement of ground branch road and the detection of stake resistance achieve a butt joint.This detection mode because of be subjected to bus over the ground between capacitive effect bigger, so precision be difficult to guarantee, but also more or less straight-flow system is impacted.

Utility model content the utility model is realized insulating monitoring by the output signal that is enclosed within the leakage current sensor on each branch road, after earth fault appears in certain bar branch road, this sensor can output signal, computing machine this signal of just sampling, judge the ground connection branch road, calculate stake resistance and ground voltage,, therefore can not have any impact straight-flow system so need not on bus or branch road, to inject AC signal.

For realizing the purpose of the utility model insulating monitoring, design proposal is as follows:

Straight-flow system insulating monitoring instrument comprises: the control of microprocessor and unit, store loop are made of microprocessor, the user program memory with control program, user data memory, address latch, 3-8 code translator, house dog; Keyboard display unit is made of liquid crystal display district, intelligent keyboard and display process circuit part, user's key entry area; Bus expansion, signals collecting, conversion, processing unit distribute district, chip selection signal distribution, analog to digital conversion, I/O expansion area, fault handling district, signal input field to constitute by sequential; Also comprise a power supply.

The utility model adopts high precision leakage current sensor and Microcomputer Controling Technique, and the man-machine interface that has adopted the Hanzify liquid crystal display to show, can understand system running state easily and intuitively, and can pass through the upper and lower alarming value of keyboard to set up I, II section busbar voltage and the alarming value of busbar grounding resistance, to be suitable for the various specific function requirements of different user.When certain bar branch road generation earth fault of straight-flow system, this device can be found the polarity of its ground connection rapidly, road number (in the simulation displayed map cursor flash the loop be the earth fault loop) grounding resistance and affiliated bus hop count; Can be on the ground connection date, time keeping gets off, and exports to user's master system for user inquiring or data by serial port, concentrates for the user to monitor; Can I, the II section busbar voltage of straight-flow system be monitored, the upper limit value and lower limit value of busbar voltage is carried out off-limit alarm (alarming value can be adjusted by the user), type of alarm has taked the panel red led to flash and sound equipment is reminded operating personnel, also provides one group of normally opened contact to use for user's centralized control simultaneously; This monitor can be used in the straight-flow system of one section bus, also can monitor two sections independently DC bus system.The standard configuration of this monitor is 1-32 loop of I section bus, and II section bus is 1-32 loop, also can suitably adjust according to user's actual conditions; System has the date, and clock shows that the user can revise in real time to it; This monitor is furnished with RS-422 and RS-485 interface, the operation information of equipment can be reached host computer by the communication protocol of unanimity, for system's Centralized Monitoring.

Description of drawings Fig. 1 is a straight-flow system insulating monitoring instrument composition frame chart; Fig. 2 is the control and unit, the store loop schematic diagram of microprocessor; Fig. 3 is the keyboard display unit schematic diagram; Fig. 4-a, Fig. 4-b are bus expansion, signals collecting, conversion, processing unit schematic diagram; Fig. 5 is the control program process flow diagram of microprocessor.

Be straight-flow system insulating monitoring instrument circuit to be formed to do more detailed description in conjunction with the accompanying drawings below the embodiment.

Shown in the accompanying drawing 1, straight-flow system insulating monitoring instrument comprises control and unit, store loop 1, keyboard display unit 2, bus expansion, signals collecting, conversion, processing unit 3 and the power supply 4 of microprocessor.

Shown in the accompanying drawing 2, the control of microprocessor and unit, store loop are made up of control zone, user program memory 27256, user data memory 6264, address latch 744S573,3-8 code translator 74LS138, the house dog of 89C51 microprocessor.In the control and storage unit of microprocessor, adopt address latch 74AS573 to be used for carrying out latching of least-significant byte address, by its growth data storer and program storage.89C51 has the microprocessor of inner EEPROM, can select by inside/outside storer selector switch EA, uses inner EEPROM when the EA pin connects high level, uses external program memory when the EA pin connects low level.A, B, C tripod that P22, P23, the P24 of the P2 mouth of microprocessor meets code translator 74LS138 produce 8 (Y0-Y7) chip selection signals, and wherein Y1, Y3 meet two AD574, and YO connects 8255.ALE connects the C pin of 74AS573, and PSEN connects 27256 OE and 6264 CS2 pin.

Shown in the accompanying drawing 3, keyboard display unit is made of liquid crystal MGL240128T, 74AS573.In this unit, select MGL240128T for use, the dot lcd graphic display control.Character has hardware setting, can graphics mode, and text mode and graph text synthesis mode show that this device is made sampled data with it and shown that 74AS573 controls keyboard by latch.

Shown in accompanying drawing 4-a, Fig. 4-b, bus expansion, signals collecting, conversion, processing unit, outside sampled signal LM358 amplifies and sends AD7506 to and carry out passage and switch in this unit, switches 16 * 4 tunnel signals collecting by 4 AD7506.Again signal is sent to the input/output port of expanding by 8255, two AD574 carry out the digital-to-analog conversion of four road voltages, electric current, microprocessor is handled by the sampled data of AD574, has judged whether fault, sends the fault sound and light alarm when breaking down.

Shown in the accompanying drawing 5, the control program process flow diagram of microprocessor.Beginning system and liquid crystal are carried out initialization STEP=0, forward corresponding ports to according to the numerical value of STEP and control, when STEP=0, is to handle keyboard and display routine.When STEP=1, be to carry out data acquisition and analyze computing.When STEP=2, be to carry out fault alarm and handling procedure.Program is carried out circular treatment according to the variation of STEP, finishes up to artificial shutdown.

Claims

1, a kind of straight-flow system insulating monitoring instrument, it is characterized in that monitoring instrument comprises: the control of microprocessor and unit, store loop are made of control zone, user program memory, user data memory, address latch, 3-8 code translator, the house dog of microprocessor; Keyboard display unit is made of liquid crystal display district, intelligent keyboard and display process circuit part, user's key entry area; Bus expansion, signals collecting, conversion, processing unit distribute district, chip selection signal distribution, analog to digital conversion, I/O expansion area, fault handling district, signal input field to constitute by sequential; Also comprise a power supply.

2, the monitor of the described straight-flow system state of insulation of claim 1 is characterized in that in the control and storage unit of microprocessor, adopts address latch 74AS573 to be used for carrying out latching of least-significant byte address, by its growth data storer and program storage; Keyboard display unit is made of liquid crystal MGL240128T, 74AS573; In bus expansion, signals collecting, conversion, the processing unit, switch 16 * 4 tunnel signals collecting by 4 AD7506, two AD574 carry out the digital-to-analog conversion of four road voltages, electric current.