阅读说明：本技术 一种开关量采样装置及方法 (Switching value sampling device and method ) 是由 门殿卿 阮青亮 吴焱 吴凯 牟晋力 史志伟 岳峰 张尧 董金才 于 2021-08-05 设计创作，主要内容包括：本发明公开了一种开关量采样装置,包括控制器件、电阻网络、稳压器件、隔离器件和开关器件；电阻网络的输入端和稳压器件的输入端分别为开入信号的正输入端和负输入端,电阻网络的输出端和稳压器件的输出端分别连接隔离器件的正输入端和负输入端,隔离器件的输出端连接控制器件,开关器件与稳压器件并联,开关器件的控制端连接控制器件。同时公开了相应的方法。本发明通过开关器件控制稳压器件在开入回路中的状态,可在各种状态下测量隔离器件隔离后副边输出电压,经过数学计算,能准确得出开入信号电压值。(The invention discloses a switching value sampling device, which comprises a control device, a resistance network, a voltage stabilizing device, an isolating device and a switching device, wherein the control device is connected with the resistance network; the input end of the resistance network and the input end of the voltage stabilizing device are respectively a positive input end and a negative input end of an incoming signal, the output end of the resistance network and the output end of the voltage stabilizing device are respectively connected with the positive input end and the negative input end of the isolation device, the output end of the isolation device is connected with the control device, the switching device is connected with the voltage stabilizing device in parallel, and the control end of the switching device is connected with the control device. A corresponding method is also disclosed. The invention controls the state of the voltage stabilizing device in the open-circuit loop through the switching device, can measure the secondary output voltage after the isolation of the isolation device in various states, and can accurately obtain the voltage value of the open-circuit signal through mathematical calculation.)

1. A switching value sampling device is characterized by comprising a control device, a resistance network, a voltage stabilizing device, an isolating device and a switching device;

the input end of the resistance network and the input end of the voltage stabilizing device are respectively a positive input end and a negative input end of an incoming signal, the output end of the resistance network and the output end of the voltage stabilizing device are respectively connected with the positive input end and the negative input end of the isolation device, the output end of the isolation device is connected with the control device, the switching device is connected with the voltage stabilizing device in parallel, and the control end of the switching device is connected with the control device.

2. The switching value sampling device according to claim 1, wherein when the switching device is closed, the internal resistance of the switching device is less than 0.01 Ω; when the switching element is opened, the internal resistance of the switching element is more than 100 MOmega; and when the voltage value of the input signal is calculated, the influence of the internal resistance of the switching element is ignored.

3. The switching value sampling device according to claim 1, wherein the resistance value of the resistor network satisfies the following condition:

the maximum current on the resistor network is smaller than the maximum reverse current of the voltage stabilizing device;

the maximum current on the resistance network is converted through the isolation device, the output voltage signal range of the isolation device covers the open signal voltage range, and the maximum open signal voltage is guaranteed not to exceed the saturation voltage of the secondary side of the isolation device.

4. The switching value sampling apparatus according to claim 1, wherein the voltage regulator device satisfies the following condition:

the reverse voltage stabilization of the voltage stabilization device is less than the minimum recognizable input signal voltage;

the reverse voltage stabilization of the voltage stabilizing device causes the variation of the output signal of the isolating device to be larger than the minimum resolution of ADC sampling of the control device through the on-off of the switch device.

The voltage stabilizing value of the voltage stabilizing device is kept unchanged when the voltage stabilizing device is connected in series into the open-circuit loop every time.

5. The switching value sampling device according to claim 1, wherein the isolation device delivers the on-signal current to the control device ADC in a linear amplification or in an equal proportion.

6. A switching value sampling device according to claim 4, wherein the amplification factor of the isolation device is constant during switching of the switching device.

7. The method for sampling the switching value of the switching value sampling device according to any one of claims 1 to 6, comprising the following steps:

sending a connection communication to a switching deviceCollecting voltage value V of output signal of isolation device_AIN1；

Sending a disconnection signal to the switching device, and collecting the voltage value V of the output signal of the isolation device_AIN2；

According to V_AIN1And V_AIN2And calculating the voltage value of the input signal.

8. The method of claim 7, wherein the open-signal voltage value is calculated by the following formula:

wherein, V_INFor switching in the signal voltage value, V_WYIs the reverse voltage of the voltage regulator device.

Technical Field

The invention relates to a switching value sampling device and method, and belongs to the technical field of power system protection automation.

Background

The input of the switching value of the comprehensive automation system of the transformer substation mainly comprises a switching value input circuit (open circuit), a circuit breaker, a disconnecting switch and the like. The circuit breakers and the isolating switches are all arranged in a high-voltage loop and have strong electromagnetic interference capacity, so that an incoming signal generally needs to be isolated before being collected, the currently widely used isolating processing method is to realize photoelectric isolation by adopting an optical coupler, and the incoming signal is difficult to measure and calculate due to the fact that a switching value output mode is judged by a digital level 0/1 output by the optical coupler.

Disclosure of Invention

The invention provides a switching value sampling device and a switching value sampling method, which solve the problems disclosed in the background technology.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a switching value sampling device comprises a control device, a resistance network, a voltage stabilizing device, an isolating device and a switching device;

the input end of the resistance network and the input end of the voltage stabilizing device are respectively a positive input end and a negative input end of an incoming signal, the output end of the resistance network and the output end of the voltage stabilizing device are respectively connected with the positive input end and the negative input end of the isolation device, the output end of the isolation device is connected with the control device, the switching device is connected with the voltage stabilizing device in parallel, and the control end of the switching device is connected with the control device.

When the switching element is closed, the internal resistance of the switching element is less than 0.01 omega; when the switching element is opened, the internal resistance of the switching element is more than 100 MOmega; and when the voltage value of the input signal is calculated, the influence of the internal resistance of the switching element is ignored.

The resistance value of the resistance network meets the following conditions:

the maximum current on the resistor network is smaller than the maximum reverse current of the voltage stabilizing device;

the maximum current on the resistance network is converted through the isolation device, the output voltage signal range of the isolation device covers the open signal voltage range, and the maximum open signal voltage is guaranteed not to exceed the saturation voltage of the secondary side of the isolation device. The voltage stabilizing device meets the following conditions:

the reverse voltage stabilization of the voltage stabilization device is less than the minimum recognizable input signal voltage;

the reverse voltage stabilization of the voltage stabilizing device causes the variation of the output signal of the isolating device to be larger than the minimum resolution of ADC sampling of the control device through the on-off of the switch device.

The isolation device transmits the open-circuit signal current to the control device in linear amplification or equal proportion.

The amplification factor of the isolation device is unchanged in the on-off process of the switch device. When the switch device is closed, the internal resistance of the switch device is less than 0.01 omega, when the switch device is opened, the internal resistance of the switch device is more than 100M omega, and the influence of the internal resistance of the switch device on a system can be ignored during calculation.

A method of switching a sampling device, comprising:

sending a switch-on signal to the switching device, and collecting the voltage value V of the output signal of the isolating device_AIN1；

Sending a disconnection signal to the switching device, and collecting the voltage value V of the output signal of the isolation device_AIN2；

According to V_AIN1And V_AIN2And calculating the voltage value of the input signal.

The open-in signal voltage value calculation formula is as follows:

wherein, V_INFor switching in the signal voltage value, V_WYIs the reverse voltage of the voltage regulator device.

The invention achieves the following beneficial effects: the invention controls the state of the voltage stabilizing device in the open-circuit loop through the switching device, can measure the secondary output voltage after the isolation of the isolation device in various states, and can accurately obtain the voltage value of the open-circuit signal through mathematical calculation.

Drawings

FIG. 1 is a block diagram of the apparatus of the present invention.

Detailed Description

The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

As shown in fig. 1, a switching value sampling apparatus includes a control device, a resistor network, a voltage regulator device, an isolation device, and a switching device.

The input end of the resistance network and the input end of the voltage stabilizing device are respectively a positive input end and a negative input end of an incoming signal, the output end of the resistance network and the output end of the voltage stabilizing device are respectively connected with the positive input end and the negative input end of the isolation device, the output end of the isolation device is connected with the control device, the switching device is connected with the voltage stabilizing device in parallel, and the control end of the switching device is connected with the control device.

The device controls the state of the voltage stabilizing device in the open-circuit loop through the switching device, can measure the secondary output voltage after the isolation of the isolation device in various states, and can accurately obtain the voltage value of the open-circuit signal through mathematical calculation, thereby judging whether the open-circuit signal is effective or not, namely the action voltage of the open-circuit signal meets the action range of 55-70%.

The resistance network, the voltage stabilizing device, the isolating device and the switch device form an open-in loop.

An isolation device in the open loop samples a linear optocoupler or other isolation devices and can isolate an open signal from an internal signal; the isolation device has the function of transmitting the open-in signal current to the control device in a linear amplification or equal proportion, can have any amplification factor, and only needs to ensure that the linearity of the isolation device is consistent within the range of measurable open-in voltage and does not exceed the ADC sampling range of the control device.

The switch device adopts a controllable switch device, the on-off of a switch contact of the switch device is controlled by a SW signal controlled by the control device, the on-off time of the switch device is required to be as short as possible, and the amplification factor of the isolation device is kept unchanged in the on-off operation process of the switch device.

When the switching element is closed, the internal resistance of the switching element is less than 0.01 omega; when the switching element is opened, the internal resistance of the switching element is more than 100 MOmega; and when the voltage value of the input signal is calculated, the influence of the internal resistance of the switching element is ignored.

The resistance value of the resistance network meets the following conditions:

1) the maximum current on the resistor network is smaller than the maximum reverse current of the voltage stabilizing device;

2) the maximum current on the resistance network is converted through the isolation device, the output voltage signal range of the isolation device covers the open signal voltage range, and the maximum open signal voltage is guaranteed not to exceed the saturation voltage of the secondary side of the isolation device.

The voltage stabilizing device is a voltage stabilizer and meets the following conditions:

1) the reverse voltage stabilization of the voltage stabilization device is less than the minimum recognizable input signal voltage;

2) the reverse voltage stabilization of the voltage stabilizing device causes the variation of the output signal of the isolating device to be larger than the minimum resolution of ADC sampling of the control device through the on-off of the switch device.

In summary, the parameters of the voltage regulator device, the resistor network and the voltage regulator device should satisfy the following requirements:

V_INmin≥V_WY

wherein, V_INmaxIs the maximum recognizable on-voltage value, V, of the whole device_INminIs the minimum recognizable value of the on-voltage, V_AINmaxIs a control device ADC maximum sampling voltage, V_AINminIs the minimum sampling voltage of the control device ADC, mu is the amplification factor of the isolation device V_WYFor the reverse voltage of the voltage-stabilizing device (reverse voltage in open loop), I_WYmaxIs the maximum reverse leakage current of the voltage stabilizing device, and R is the series resistance of the resistance network in the open loop.

The control device is a CPU with an ADC (analog to digital converter), or the ADC and the CPU adopt discrete devices, the CPU has the calculation capability and performs mathematical operation on the sampling value of the ADC so as to obtain an input voltage value, and the CPU has a controllable IO pin.

The traditional optocoupler device belongs to an analog device, the change of temperature can cause the change of a transmission ratio (CTR) to be large, so that the action voltage of an input signal can change along with the change of the CTR of each optocoupler at different temperatures, and a loop needs to be calibrated to obtain a real input signal voltage; the device does not need to obtain the exact conversion coefficient of the isolation device, only needs to make requirements on the transmission coefficient ranges of the resistance network and the isolation device during design, and ensures that the output voltage of the isolation device can cover the maximum input signal voltage in the operation process without calibration.

The method for switching the sampling device comprises the following steps:

step 1, sending a switch-on signal to a switching device, and acquiring a voltage value V of an output signal of an isolating device_AIN1；

V_AIN1＝μ₁V_IN1Wherein, mu₁Is the amplification factor, V, of the isolating device at this moment (at the moment when the switching device is switched on)_IN1Is the value of the switching voltage at this moment (the moment when the switching device is switched on);

step 2, sending a disconnection signal to the switch device, and acquiring a voltage value V of an output signal of the isolation device_AIN2；

V_AIN2＝μ₂(V_IN2-V_WY) Wherein, mu₂Is the amplification of the isolation device at this moment (at the moment of switching-off of the switching device)Coefficient, V_IN2Is the value of the switch-on voltage, V, at this moment (the moment of switching-off of the switching device)_WYIs the reverse voltage of the voltage regulator device;

step 3, according to V_AIN1And V_AIN2Calculating the voltage value of the input signal;

considering that the on-off operation time of the switching device is short, μ is considered to be₁＝μ₂，V_IN1＝V_IN2Therefore, the value of the input signal voltage is:

wherein, V_INIs the value of the on signal voltage.

The method is directly applied to the control device to control the on-off of the switch device, so that the series state of the voltage stabilizing device in the open-circuit loop is controlled, the control device collects voltage signals in different states, and the actual value of the open-circuit voltage is calculated.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.