CN105699927A - DC system insulation monitor calibration device - Google Patents

Abstract

The invention discloses a DC system insulation verification device, which comprises a voltage acquisition module, an AD acquisition module, a data processing module, a watchdog module, a grounding resistance array, a grounding capacitance array, an adjustable DC power supply module, and an AC power supply module , the man-machine interface module, the voltage acquisition module is connected to the AD acquisition module, the AD acquisition module is connected to the data processing module, the watchdog module and the man-machine interface module are also respectively connected to the data processing module, and the data processing module simultaneously controls the grounding resistance array, grounding Capacitor arrays, adjustable DC power modules, and AC power modules. The coordinated work among the various modules of the invention can realize all-round verification of functions such as insulation monitoring, insulation reduction, AC channeling, and system resistance to distributed capacitance, so as to ensure the safe operation of the DC power supply under reliable monitoring.

Description

DC system insulation monitoring and verification device

technical field

The invention relates to an insulation monitoring and checking device for DC systems in substations and power plants.

Background technique

In order to ensure the safety and reliability of the power system, the working power sources of relay protection and automatic control devices, circuit breaker control and energy storage in power plants and substations all use DC power sources stored in batteries. When the DC power supply is grounded at one point, the grounding line and the grounding point must be found as soon as possible, otherwise, once the second point is grounded, the relay or protection device may malfunction or refuse to operate, resulting in a leapfrog trip and a major accident. Therefore, insulation monitoring is essential for substations and power plants. However, when installing or replacing insulation monitoring in many substations, the DC system is in the running state, and it is impossible to inspect functions such as insulation reduction and AC channeling, and after a period of insulation monitoring, it is impossible to determine whether the equipment is in good condition. There is a big security risk.

Contents of the invention

In order to eliminate the potential safety hazards in the above DC system, the present invention aims to provide a DC system insulation monitoring and verification device with high reliability, strong stability and good safety, which can realize insulation monitoring, insulation reduction, AC channeling, and system All-round verification of anti-distributed capacitance and other functions to ensure the safe operation of the DC power supply under reliable monitoring.

In order to achieve the above object, the present invention adopts the technical scheme as follows:

A DC system insulation verification device is divided into a voltage acquisition module, an AD acquisition module, a data processing module, a watchdog module, a grounding resistance array, a grounding capacitor array, an adjustable DC power supply module, an AC power supply module, and a man-machine interface module. The voltage acquisition module is connected to the AD acquisition module, and the AD acquisition module is connected to the data processing module. The watchdog module and the man-machine interface module are also respectively connected to the data processing module. The data processing module simultaneously controls the grounding resistor array, the grounding capacitor array, the adjustable DC Power module and AC power module.

The voltage acquisition module is used to convert the received voltage signal into a signal suitable for acquisition by the AD acquisition module. Through the principle of resistive voltage division, a high-precision sampling resistor is used to convert a larger voltage signal into a smaller voltage signal, and the small voltage signal is converted into a signal suitable for AD acquisition module through a signal conditioning circuit.

The AD acquisition module is used to convert the analog signal of the voltage acquisition module into a digital signal read by the data processing module, so as to obtain the magnitude of the voltage signal. The AD acquisition module of the present invention adopts a 16-bit high-speed AD chip.

The data processing module receives the digital signal of the AD acquisition module, obtains the magnitude of the voltage signal, and reads the information set by the man-machine interface module, and then controls the grounding resistance array, the grounding capacitor array, the adjustable DC power supply module and the AC power supply module according to Set requirements to work. The data processing module of the present invention adopts a 32-bit floating-point digital signal processor. It is an industrial-grade high-performance DSP chip that can be used in harsh environments and is the core component of the entire product. 88 independently programmable multiplexed general-purpose input/output (GPIO) pins, with up to 4 optional working modes, which can meet the needs of logic control for GPIO.

The watchdog module is used to prevent the CPU of the data processing module from crashing (such as crashes caused by strong interference, unstable power supply, etc.), and to ensure the normal operation of the device.

Ground resistance array, mainly used to verify the insulation reduction alarm of insulation monitoring. The module has a set of independent grounding resistor arrays between the positive and negative poles and the ground, which are composed of high-power and high-precision resistors with different resistance values. Each resistor corresponds to a relay. The data processing module controls the on-off of different relays. The principle of resistors in series can be combined to obtain more resistance values.

The ground capacitor array is mainly used to verify the system anti-distributed capacitance of the insulation monitoring. The module has a set of independent ground capacitor arrays between the positive and negative poles and the ground, which are composed of non-polar capacitors of different sizes. Each capacitor corresponds to A relay, the data processing module controls the on-off of different relays, and more capacitance values can be obtained through the combination of capacitors in parallel.

The adjustable DC power supply module is mainly used to provide DC power for insulation monitoring and to verify the DC voltage monitoring of insulation monitoring. It is composed of adjustable DC power supply and DA output circuit. The adjustable DC power supply is used to output DC voltage. The output size of DC voltage is determined by the size of the input control voltage. The data processing module realizes the control voltage signal output by controlling the DA output circuit. Control of DC voltage output.

The AC power module is mainly used to verify the AC channeling monitoring and alarm functions of the insulation monitoring. It consists of a transformer with two outputs, the input voltage is AC220V, and the AC voltage is controlled by the on and off of the relay.

The human-machine interface module is used for interaction and information exchange between the device and the user. The man-machine interface module of the present invention is composed of a high-resolution touch screen, and the operation of all functions of the device is realized through the touch screen. In the setting interface, a variety of input forms of check boxes are introduced, and the setting of various complex combination function items can be completed by checking. The humanized man-machine interface also includes friendly user prompts. When some function items are tested, detailed prompts will appear on the LCD interface to guide the smooth completion of the test process.

The voltage acquisition module, AD acquisition module, data processing module, watchdog module, grounding resistance array, grounding capacitance array, adjustable DC power supply module, AC power supply module and man-machine interface module of the DC system insulation verification device of the present invention coordinate with each other Working, it can realize the all-round verification of the insulation monitoring and insulation reduction of the DC system, AC channeling, system anti-distributed capacitance and other functions. Its voltage acquisition has high precision, good reliability, and can safely and conveniently verify the insulation monitoring. In addition, the invention is small in size and convenient to move, and is suitable for checking insulation monitoring in different places.

Description of drawings

Fig. 1 is a schematic diagram of module combination of the present invention.

detailed description

The present invention will be further described below in conjunction with accompanying drawing:

As shown in Figure 1, the DC system insulation verification device is divided into voltage acquisition module, AD acquisition module, data processing module, watchdog module, grounding resistance array, grounding capacitor array, adjustable DC power supply module, AC power supply module, Human-machine interface module. The voltage acquisition module is connected to the AD acquisition module, and the AD acquisition module is connected to the data processing module. The watchdog module and the man-machine interface module are also respectively connected to the data processing module. The data processing module simultaneously controls the grounding resistor array, the grounding capacitor array, the adjustable DC Power module and AC power module.

Connect the busbar input port of the insulation monitoring to the DC voltage output port of the DC system insulation monitoring and verification device, and select the corresponding verification function by operating the touch screen of the man-machine interface module according to the function to be verified.

Verification of the insulation reduction alarm function: by setting the man-machine interface, select the resistance value and polarity to be verified, the data processing module controls the conduction of the corresponding relay of the resistance array by reading the setting information, and achieves the verification resistance through the series connection of the resistance Value, to realize the verification of this function.

Calibration of AC channeling monitoring and alarm function: by setting the man-machine interface, select the AC voltage value and polarity to be verified, and the data processing module controls the conduction of the corresponding relay by reading the setting information to introduce the AC quantity for testing , to realize the verification of this function.

Calibration of the system anti-distributed capacitance function: by setting the man-machine interface, select the capacitance value and polarity to be verified, and the data processing module controls the conduction of the corresponding relay of the capacitor array by reading the setting information, and achieves the verification through the parallel connection of the capacitors Capacitance value, to simulate the actual capacitive interference, to realize the verification of this function.

Claims (8)

1. A DC system insulation verification device, characterized in that it includes a voltage acquisition module, an AD acquisition module, a data processing module, a watchdog module, a grounding resistor array, a grounding capacitor array, an adjustable DC power supply module, and an AC power supply module , the man-machine interface module, the voltage acquisition module is connected to the AD acquisition module, the AD acquisition module is connected to the data processing module, the watchdog module and the man-machine interface module are also respectively connected to the data processing module, and the data processing module simultaneously controls the grounding resistance array, grounding Capacitor array, adjustable DC power module and AC power module; The voltage acquisition module is used to convert the received voltage signal into a signal suitable for the AD acquisition module to collect; The AD acquisition module is used to convert the analog signal of the voltage acquisition module into a digital signal read by the CPU; The data processing module receives the digital signal of the AD acquisition module, obtains the magnitude of the voltage signal, and reads the information set by the man-machine interface module, and then controls the grounding resistor array, the grounding capacitor array, the adjustable DC power supply module and the AC power supply The module works according to the set requirements; The watchdog module is used to prevent the CPU of the data processing module from crashing; The grounding resistance array is mainly used to verify the insulation reduction alarm of insulation monitoring; The ground capacitance array is mainly used for checking the system anti-distributed capacitance of insulation monitoring; The adjustable DC power supply module is mainly used to provide DC power for insulation monitoring, and to verify the DC voltage monitoring function of insulation monitoring; The AC power supply module is mainly used for AC channeling monitoring and alarm for insulation monitoring; The man-machine interface module is used for interaction and information exchange between the device and the user. 2. The DC system insulation monitoring and verification device according to claim 1, characterized in that the voltage acquisition module adopts the principle of resistance voltage division to obtain small voltage signals, and the small voltage signals are connected to the signal conditioning circuit to convert the small voltage signals into suitable AD The signal collected by the acquisition module. 3. The DC system insulation monitoring and verification device according to claim 1, wherein the AD acquisition module adopts a 16-bit high-speed AD chip. 4. The DC system insulation monitoring and verification device according to claim 1, wherein the data processing module adopts a 32-bit floating-point digital signal processor. 5 . The DC system insulation monitoring and verification device according to claim 1 , wherein the grounding resistance array is put into operation in such a way that the data processing module realizes the series connection of different resistances by controlling the on and off of the relay. 5 . 6. The DC system insulation monitoring and verification device according to claim 1, characterized in that, the input method of the grounded capacitor array is that the data processing module realizes the parallel connection of different capacitors by controlling the on-off of the relay. 7. The DC system insulation monitoring and verification device according to claim 1, wherein the adjustable DC power supply module is composed of an adjustable DC power supply and a DA output circuit, and the output of the DC voltage of the adjustable DC power supply is data The processing module is controlled by controlling the output of the DA chip. 8. The DC system insulation monitoring and verification device according to claim 1, wherein the output of the AC voltage of the AC power module is fixed output through a transformer.