Apparatus, system, and method for measuring high voltage on a high-voltage node

Abstract

A device (20) for measuring a high voltage on a high voltage node, the power electronic converter comprising a first AC-DC converter (21), a first DC-AC converter (22) and a second AC-DC converter (23), the first AC-DC converter being connected to a low voltage arm of a high voltage divider coupled between the high voltage node and the device to obtain a voltage measurement signal, the first DC-AC converter being configured to output a modulated signal of the voltage measurement signal and the second AC-DC converter being configured to output a demodulated signal of the voltage measurement signal; an apparatus comprising: a high frequency transformer (24) having a primary coil connected to an output terminal of the DC-AC converter to receive the modulated signal, and a secondary coil connected to an input terminal of the second AC-DC converter; and a controller (25) configured to provide control signals to control switching elements of the first DC-AC converter to control a turn-on sequence of each switching element such that the first DC-AC converter outputs the modulated signal, calculate signal parameters including phase information and amplitude information of a high voltage on the high voltage node, and output the calculated signal parameters.

Description

[Technical Field]

[0001] Technical field This disclosure relates to a solution for measuring high voltage on a high-voltage node. [Background technology]

[0002] background Capacitor voltage transformers (CVTs) are widely used in high-voltage applications. Conventional CVTs found in prior art typically include a capacitor voltage divider (CVD) and an electromagnetic unit (EMU). According to the operating principle of conventional CVTs, the high voltage on a high-voltage node is first stepped down by the CVD, then supplied to an intermediate voltage transformer (IVT) in the EMU to be further stepped down to a lower voltage, and then supplied to a meter or protective relay connected to the user equipment. However, such conventional CVTs have several limitations. Because CVTs include energy storage components (e.g., capacitors and inductors) designed to resonate at a fundamental frequency (e.g., 50Hz / 60Hz) during normal operation, measurement accuracy for measuring high voltages can only be guaranteed at the fundamental frequency, and harmonic detection cannot be achieved. Furthermore, the damping reactor must be connected in parallel to the secondary residual winding of the EMU to dampen iron resonance, and the tap voltage from the CVD should exceed 10kV; otherwise, the resonant energy cannot be dampened. Thus, to output a low voltage of approximately 100V, a large magnetic core with a high turns ratio must be used for the IVT, which increases the cost and volume of the CVT, and a high level of insulation in the IVT is required to meet the requirement of a high tap voltage from the CVD. [Overview of the project] [Problems that the invention aims to solve]

[0003] overview This summary is provided to introduce a group of concepts that will be further explained in the detailed description below. It is not intended to identify any significant or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. [Means for solving the problem]

[0004] In consideration of the above-mentioned problems in the prior art, the present disclosure provides, in one embodiment, an apparatus for measuring high voltage on a high-voltage (HV) node, the apparatus being a power-electronic converter comprising a first AC-DC converter, a first DC-AC converter, and a second AC-DC converter, wherein the first AC-DC converter is connected to the low-voltage arm of a high-voltage divider coupled between the HV node and the apparatus to acquire a voltage measurement signal, the first DC-AC converter is configured to output a modulated signal of the voltage measurement signal, and the second AC-DC converter outputs a demodulated signal of the voltage measurement signal. The system comprises a power electronic converter, a high-frequency transformer having a primary coil connected to the output terminal of a first DC-AC converter to receive a modulation signal, and a secondary coil connected to the input terminal of a second AC-DC converter, and a controller configured to supply control signals for controlling the switching elements of the first DC-AC converter to control the turn-on sequence of each switching element so that the first DC-AC converter outputs a modulation signal, calculate signal parameters including phase and amplitude information of high voltages on high voltage nodes, and output the calculated signal parameters.

[0005] In another embodiment, this disclosure provides a system for measuring high voltage on a high-voltage (HV) node, the system comprising a high-voltage divider connected to the HV node and a measuring device provided in a terminal box coupled to the high-voltage divider, the measuring device being a power electronic converter comprising a first AC-DC converter, a first DC-AC converter, and a second AC-DC converter, wherein the first AC-DC converter is connected to the low-voltage arm of the high-voltage divider to acquire a voltage measurement signal, the first DC-AC converter is configured to output a modulated signal of the voltage measurement signal, and the second AC-DC converter is configured to output a modulated signal of the voltage measurement signal The measuring device includes a power electronic converter configured to output a demodulated signal; a high-frequency transformer comprising a primary coil connected to the output terminal of a first DC-AC converter to receive a modulated signal and a secondary coil connected to the input terminal of a second AC-DC converter; and a controller configured to supply control signals for controlling the switching elements of the first DC-AC converter to control the turn-on sequence of each switching element so that the first DC-AC converter outputs a modulated signal, calculate signal parameters including phase and amplitude information of high voltages on high voltage nodes, and output the calculated signal parameters.

[0006] In yet another embodiment, the Disclosure provides a method for measuring a high voltage on a high-voltage node using a measuring device, the measuring device comprising a power electronic converter, a high-frequency transformer, and a controller, wherein the power electronic converter comprises a first AC-DC converter, a first DC-AC converter, and a second AC-DC converter, the first AC-DC converter being configured to acquire a voltage measurement signal of the high voltage on the high-voltage node, the first DC-AC converter being configured to output a modulated signal of the voltage measurement signal, the second AC-DC converter being configured to output a demodulated signal of the voltage measurement signal, the high-frequency transformer being coupled between the first DC-AC converter and the second AC-DC converter to transmit the modulated signal, the method comprising supplying control signals to the switching elements of the first DC-AC converter in the controller to control the turn-on sequence of each switching element so that the first DC-AC converter outputs a modulated signal, the method further comprising calculating signal parameters of phase information and amplitude information of the high voltage on the high-voltage node in the controller, and outputting the calculated signal parameters.

[0007] Brief explanation of the drawing The disclosed aspects are described below in relation to the accompanying drawings, which are provided for illustrative purposes only and do not limit the scope of this disclosure. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic block diagram of a system for measuring high voltage on a high-voltage node, as an example of the present disclosure. [Figure 2] This is a schematic block diagram of the measuring device of the system shown in Figure 1, as an example of this disclosure. [Figure 3] Figure 1 is a schematic block diagram of the measuring device for the system shown, according to another example of this disclosure. [Figure 4] Figure 2 shows an exemplary embodiment of the measuring device. [Figure 5] Figure 2 shows another exemplary embodiment of the measuring device. [Figure 6]Another exemplary embodiment of the measuring device shown in FIG. 2 is shown. [Figure 7] An exemplary embodiment of the measuring device shown in FIG. 3 is shown. [Figure 8] It is a flowchart of a method for measuring a high voltage on a high voltage node according to an example of the present disclosure. [Figure 9] Exemplary simulation results according to an example of the present disclosure are shown. [Figure 10] Exemplary simulation results according to an example of the present disclosure are shown. [Figure 11] Exemplary simulation results according to an example of the present disclosure are shown.

Mode for Carrying Out the Invention

[0009] Detailed Description The present disclosure relates to a solution for measuring a high voltage without EMU, which causes many problems as described above. The solution of the present disclosure can measure a high voltage with high precision and can also provide various signal parameters including the phase and amplitude information of the high voltage. Furthermore, the solution of the present disclosure can avoid ferroresonance and reduce cost and volume. Hereinafter, examples of the present disclosure will be described.

[0010] FIG. 1 shows a system 100 for measuring a high voltage on a high voltage node according to an example of the present disclosure. The high voltage node HV may carry a DC or AC high voltage. The high voltage may be in the range of about 110 kV to 500 kV.

[0011] Referring to FIG. 1, the system 100 mainly includes a high voltage divider 10 and a measuring device 20. The high voltage divider 10 is coupled between the high voltage node HV and the measuring device 20. The measuring device 20 is coupled between the high voltage divider 10 and the user equipment UE.

[0012] The high-voltage divider 10 includes a high-voltage arm 11 and a low-voltage arm 12 connected in series between a high-voltage node HV and ground GND, and a sensing node S located between the high-voltage arm 11 and the low-voltage arm 12 is used to tap a sensing signal, i.e., a high-voltage voltage measurement signal.

[0013] In one example, the voltage division ratio of the high-voltage divider 10 may be changed by changing at least one of the high-voltage arm 11 and the low-voltage arm 12. In this example, the low-voltage arm 12 may be adjusted so that the voltage divided by the low-voltage arm 12 matches the optimized voltage required by the measuring device 20 to achieve high measurement accuracy, or the withstand voltage of the measuring device 20 for safety requirements.

[0014] The high-voltage divider 10 may be implemented as a capacitor voltage divider, a resistor voltage divider, or a hybrid divider. In one example of a capacitor voltage divider, the high-voltage arm 11 and the low-voltage arm 12 are each implemented as a voltage divider capacitor unit having one or more voltage divider capacitors. In one example of a resistor voltage divider, the high-voltage arm 11 and the low-voltage arm 12 are each implemented as a voltage divider resistor unit having one or more voltage divider resistors. In one example of a hybrid divider, the high-voltage arm 11 and the low-voltage arm 12 are each implemented as a hybrid voltage divider unit having a voltage divider capacitor and a resistor.

[0015] The measuring device 20 may be housed in a terminal box (not shown), which is coupled to the terminals of the low-voltage arm 12. According to an example of this disclosure, the measuring device 20 does not require a large magnetic core and heavy primary and secondary windings as required by prior art solutions, the volume of the measuring device 20 is reduced, and therefore the measuring device 20 can be housed in a terminal box without the problem of requiring a large space. In one example, the measuring device 20 provided in a terminal box is connected to the sensing node S (i.e., the low-voltage arm) 12It is connected via terminals and wiring. This makes it easier for the user to perform various services.

[0016] Figure 2 shows an example of a measuring device 20 coupled to a capacitor voltage divider 10 having a voltage divider capacitor C1 (functioning as a high-voltage arm 11) and a voltage divider capacitor C2 (functioning as a low-voltage arm 12).

[0017] Referring to Figure 2, the measuring device 20 comprises a power electronic converter, a high-frequency transformer 24, and a controller 25. The power electronic converter includes a first AC-DC converter 21, a first DC-AC converter 22, a second AC-DC converter 23, and a filter 26. The connection relationships and operating principles of these elements of the measuring device 20 are described below.

[0018] Continuing to refer to Figure 2, the two input terminals of the first AC-DC converter 21 are connected to the two terminals of the voltage divider capacitor C2, respectively, to obtain a high-voltage voltage measurement signal. The voltage measurement signal is converted from an AC signal to a DC signal by the first AC-DC converter 21. The output terminal of the first AC-DC converter 21 is connected to the input terminal of the first DC-AC converter 22. The first DC-AC converter 22 includes a plurality of switching elements, which may be implemented with power electronics switching elements such as MOSFETs or IGBTs. Each switching element has a control terminal that receives a control signal to control the turn-on sequence of the switching element so that the first DC-AC converter 22 outputs a modulated signal. For example, the tap voltage across capacitor C2 is supplied to a modulation unit including the first AC-DC converter 21 and the first DC-AC converter 22, and modulated into a high-frequency PWM signal. The frequency of the PWM signal may be higher than 20 kHz and higher than 50 kHz.

[0019] The high-frequency transformer 24 comprises a primary coil and a secondary coil. In one example, the turns ratio of the primary and secondary coils is between 1 and 10. The primary coil is connected to the output terminal of the first DC-AC converter 22 to receive the modulated signal, which is isolated and further stepped down to a low voltage of 100V or 100 / √3V by the high-frequency transformer 24. The secondary coil is connected to the input terminal of the second AC-DC converter 23. The further stepped-down modulated signal is demodulated by a demodulation unit including the second AC-DC converter 23 and a filter 26. The second AC-DC converter 23 outputs the demodulated signal to user-side devices such as meters and protective relays.

[0020] In one example, a filter 26 is coupled to the output terminal of the second AC-DC converter 23. The filter 26 is used to remove high-frequency components from the demodulated signal before it is output to the user-side device.

[0021] The controller 25 includes an input terminal, an output terminal, and a control terminal. The controller 25 receives sensor information from sensors associated with both the high-voltage divider 10 and the measuring device 20 via the input terminal. The controller supplies control signals via the control terminal to control the turn-on sequence of each switching element of the first DC-AC converter 22. Based on the sensor information, the controller 25 calculates signal parameters, including phase and amplitude information of the high voltage at the high-voltage nodes, and outputs the calculated signal parameters via the output terminal to user-side devices such as DSPs, MCUs, and ASICs.

[0022] The relevant sensor is the voltage across the voltage divider capacitor C2, V t A voltage sensor for measuring current I passes through a circuit branch connecting the sensing node S and the input terminal of the first AC-DC converter 21. t The device may include a current sensor for measuring the voltage and a temperature sensor for measuring the temperature of the voltage divider capacitor C2 and the ambient temperature of the measuring device 20 (for example, the temperature of the internal space of the terminal box).

[0023] Sensor information may include parameters measured by the sensor and parameters derived from the measured parameters. For example, sensor information may include the voltage V across the low-voltage divider capacitor C2 measured by the voltage sensor. t , the current I passing through the circuit branch connecting the sensing node S and the input terminal of the first AC-DC converter 21, as measured by the current sensor. t The sensor information may also include the temperature of the low-voltage divider capacitor C2 measured by a temperature probe, and the ambient temperature around the measuring device 20 measured by an ambient temperature sensor. The sensor information may also include parameters calculated based on the measured parameters. The calculation may be performed by a processor integrated with the sensor or a processor integrated with the controller. For example, the sensor information may include the angular frequency of the tap voltage signal, the impedance of the measuring device 20, and the temperature shift of the device of the measuring device 20. The method for calculating these parameters is not limited in this disclosure.

[0024] In one example, the calculated signal parameters may include at least one of the following: the peak voltage magnitude, RMS value, polarity, phase value, harmonic value, and waveform of the high voltage. The signal parameters may also include a phase offset between the phase of the high voltage signal and that of the voltage measurement signal. The signal parameters may also include an amplitude deviation between the amplitude of the high voltage signal and the amplitude of the voltage measurement signal.

[0025] It is advantageous to provide signal parameters since the power quality from the high voltage node can be measured based on those signal parameters. Further, power quality issues (e.g., sag / surge, harmonic distortion and inter-harmonics, spike / transient, under-voltage / over-voltage) that can affect the operation and efficiency of electrical equipment can be detected in a timely manner. As a result, a power quality solution can be provided that maximizes the continuity of operation and ensures a smooth and continuous power supply in industrial applications. Further, protection, load control, and metering can also be realized based on the signal parameters. For example, a protection system uses the signal parameters to continuously scan for faults and enables the faulty section to be quickly disconnected from the grid. For example, the signal parameters are necessary for revenue metering and energy metering.

[0026] In one example, the controller 25 calculates a phase offset based on the following equation (1).

[0027] ΔP=k1*(ΔP C +ΔP R )+k2*(ΔP L +ΔP S )(1) In the equation, "ΔP" is the phase offset, "ΔP C " is the sub-offset due to the capacitance of the voltage dividing capacitor unit, "ΔP R " is the sub-offset due to the impedance of the measuring device 20, "ΔP L " is the sub-offset due to the leakage inductance of the measuring device 20, "ΔP S " is the sub-offset due to the parasitic capacitance of the measuring device 20, "k1" and "k2" are weights, the sum of "k1" and "k2" is equal to 1, the range of "k1" is between 0.95 and 0.99, and the range of "k2" is between 0.01 and 0.05.

[0028] In one example, the controller 25 calculates an amplitude deviation based on the following equation (2). Δa=f1*(Δa C +Δa R) + f² * Δa D (2) In the formula, "Δa" is the amplitude deviation, and "Δa C " is a partial deviation caused by the capacitance of the voltage divider capacitor unit, and "Δa R " is a partial deviation caused by the impedance of the measuring device, and "Δa D " is a partial deviation caused by the voltage drop of the measuring device 20, and "f1" and "f2" are weights, f 1" and f The sum with "2" is equal to 1, f The range for "1" is between 0.9 and 0.95, and the range for "f2" is between 0.05 and 0.1.

[0029] Furthermore, the measured / calculated signal can be compensated within the controller. For example, the measured voltage is compensated by modifying the PWM signal. The compensated measured signal can also achieve a high level of accuracy; for example, the measurement accuracy for harmonics can be up to the 60th order.

[0030] One example of this disclosure may include a pre-calibration process such as curve fitting and / or a lookup table to dynamically adjust the PWM control signal to subtly adapt to drift caused by changes in ambient conditions (e.g., changes in ambient temperature). This can further improve measurement accuracy.

[0031] The controller 25 may be implemented by hardware or software, or a combination of hardware and software, including a non-temporary computer-readable medium that is stored in memory and implemented as instructions executed by the processor. The hardware implementation may be an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a data signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a processor, a controller, a microcontroller, a microprocessor, an electronic unit, or a combination thereof. The software implementation may include microcode, program code, or code segments. The software may be stored in a machine-readable storage medium such as memory.

[0032] Figure 3 shows another example of the measuring device 20. The example in Figure 3 differs from the example in Figure 2 in that it further includes a second DC-AC converter 27 coupled between the second AC-DC converter 23 and the filter 26. The second DC-AC converter 27 may be implemented similarly to the first DC-AC converter 22. For example, the second DC-AC converter 27 includes multiple switching elements, which may be implemented with power electronics switching elements such as MOSFETs or IGBTs. Each switching element has a control terminal for receiving control signals from the controller 25 to control the turn-on sequence of the switching element. The second DC-AC converter 27 restores the high-voltage waveform and outputs an analog AC signal containing high-voltage phase and amplitude information. The frequency of the output analog signal is approximately 50 Hz. In addition, in the example in Figure 3, phase and amplitude information can also be output from the controller 25.

[0033] In the example shown in Figure 3, phase information and amplitude information may be provided by digital signals output from the controller 25 (as shown in Figure 2) and / or by analog signals output from the second DC-AC converter 27 (as shown in Figure 3). Exemplary embodiments of the measuring device 20 will be described with reference to Figures 4 to 6.

[0034] Figure 4 shows an exemplary embodiment of the measuring device 20 shown in Figure 2. Referring to Figure 4, the high-voltage side AC-DC converter 21 (i.e., the first AC-DC converter 21) consists of a rectifier with two diode half-bridges. The primary side DC-AC converter 22 (i.e., the first DC-AC converter 22) is a full-bridge converter with two half-bridges of switching elements connected in series. Each switching element is controlled by the controller 25 as described above. The secondary side AC-DC converter 23 (i.e., the second AC-DC converter 23) consists of a rectifier with two diode half-bridges, similar to that of the AC-DC converter 21. filter 26 is equipped with a capacitor for removing high-frequency components from the demodulated signal.

[0035] Figure 5 shows another exemplary embodiment of the measuring device 20 shown in Figure 2. The example in Figure 5 differs from the example in Figure 4 in that it further includes a resonant LLC circuit 28 coupled between the output terminal of the first DC-AC converter 22 and the primary side of the high-frequency transformer 24. Furthermore, the secondary AC-DC converter 23 is implemented in a different topology. For example, the secondary side AC - DC The converter 23 comprises a diode bridge rectifier and optionally a filter.

[0036] Figure 6 shows yet another exemplary embodiment of the measuring device 20 shown in Figure 2. The example in Figure 6 differs from the example in Figure 4 in that the secondary AC-DC converter 23 (i.e., the second AC-DC converter 23) is implemented as a controlled H-bridge circuit including four switching elements interconnected as an H-bridge circuit. The switching elements can be provided as power MOSFETs, IGBTs, IGCTs, etc., each having a freewheeling diode in parallel. The turn-on sequence of each switching element is controlled by the controller 25 (for example, the controller 25 supplies control signals to the control terminals of each switching element in the converter 23).

[0037] In the example shown in Figure 6, voltage adjustment and compensation for the voltage measurement signal may be performed on the secondary side. For example, the controller 25 adjusts the control signals supplied to the secondary side converter 23 so that the amplitude of the voltage measurement signal is adjusted. In one example, the controller 25 adjusts the control signals supplied to the switching elements of the secondary side converter 23 so that the amplitude of the voltage measurement signal is adjusted.

[0038] Figure 7 shows an exemplary embodiment of the measuring device 20 shown in Figure 3. 7 This example differs from the example in Figure 4 in that it further includes a secondary DC-AC converter 27 (i.e., a second DC-AC converter 27), which is a full-bridge converter with two half-bridges of series-connected switching elements controlled by a controller 25. The second DC-AC converter 27 is implemented similarly to the first DC-AC converter 22 and is a full-bridge converter with two half-bridges of series-connected switching elements. The turn-on sequence of each switching element is controlled by the controller 25.

[0039] It should be noted that the circuit of the measuring device 20 may have a different topology, and this is not limited to the examples given above. For example, a push-pull circuit is also possible. Another aspect of this disclosure, a method for measuring high voltage on a high-voltage node, is described below.

[0040] Figure 8 shows a flowchart of Method 800 for measuring high voltage on a high voltage node using a measuring device. The measuring device may be the measuring device 20 of the present disclosure, and therefore various features described above are also applicable to Method 800 with reference to the measuring device 20. Method 800 includes control and calculations performed by a controller 25.

[0041] Referring to Figure 8, in step S810, a control signal is supplied to the switching elements of the first DC-AC converter in order to control the turn-on sequence of each switching element so that the first DC-AC converter outputs a modulated signal such as a high-frequency PWM signal.

[0042] In step S820, signal parameters including phase and amplitude information of the high voltage are calculated, and the calculated signal parameters are output. In one example, the calculated signal parameters include at least one of the following: the peak voltage magnitude, RMS value, polarity, phase value, harmonic value, and waveform of the high voltage signal; a phase offset between the phase of the high voltage signal and the phase of the voltage measurement signal; and an amplitude deviation between the amplitude of the high voltage signal and the amplitude of the voltage measurement signal.

[0043] According to the examples in this disclosure, by replacing the EMU with a power electronic converter and a high-frequency transformer, transient response is improved and iron resonance is avoided. According to the examples in this disclosure, various signal detections, such as harmonic detection, are available. Cost and volume reductions can be achieved without an intermediate voltage transformer (IVT). The accuracy level for measuring high voltages can be achieved at 0.1% with the improved transient response. Furthermore, lower tap voltages are required, which not only reduces the isolation requirements of monobushings and HFTs but also lowers the withstand voltage of power electronic devices and thus the cost.

[0044] Exemplary simulation results are explained with reference to Figures 8 to 10, which show exemplary simulation results for the topology presented in Figure 4.

[0045] In Figures 9-11, the vertical axis represents voltage and the horizontal axis represents time. The topology is simulated using MATLAB® or Simulink. In Figures 9-11, "V tap " represents the tap voltage across the voltage divider capacitor C2, and "V modulate " represents the modulation voltage on the primary side, and "V secondary " represents the secondary voltage, and "V syn The symbol '' represents the combined voltage based on the polarity of the measured voltage and tap voltage. In the simulation, the high voltage was set to 110kV and the tap voltage from the capacitor divider was set to 1kV. The modulation frequency of the primary DC-AC converter was set to 20kHz. In this way, the rectified tap voltage is modulated to a 20kHz PWM-based signal and then transmitted by a high-frequency transformer with a turns ratio of 10.

[0046] Figure 9 shows the modulation voltage V, represented by the black curve, over one period (e.g., 0.02 seconds). modulate The secondary voltage V is represented by the gray curve. secondary This is shown. Figure 10 is an enlarged view of a part of Figure 9, showing the modulated voltage V modulate and secondary voltage V secondary A magnified view of the comparison can be clearly seen in Figure 9, where the frequency of the PWM pulse voltage signal is set to 20 kHz on both the primary and secondary sides of the HFT, and the voltage ratio is set to 10.

[0047] Figure 11 shows the high voltage V represented by the solid line. HV The tap voltage V is shown. tap The dashed line represents the combined voltage V syn This is represented by a dashed line. The polarity of the tap voltage is obtained to reconstruct the complete waveform of the high voltage. For example, polarity can be obtained using zero-crossing detection or a PLL.

[0048] The phase offset ΔP between the high voltage and the measured voltage can be calculated, and the combined voltage can be compensated based on the phase offset ΔP. The amplitude deviation (not shown) between the high voltage and the measured voltage can also be calculated, and the combined voltage can be compensated based on the amplitude deviation. In this way, the phase and amplitude information of the high voltage can be output by the apparatus of this disclosure.

[0049] Software should be broadly considered to represent instructions, instruction sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, execution threads, processes, functions, etc. Software can reside on non-temporary computer-readable media. Such non-temporary computer-readable media may include, for example, memory, which may be, for example, magnetic storage devices (e.g., hard disks, floppy disks, magnetic strips), optical disks, smart cards, flash memory devices, random-access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, or removable disks. In the various embodiments presented in this disclosure, memory is shown as separate from the processor, but memory may be internal to the processor (e.g., cache or registers).

[0050] The foregoing description is provided to enable those skilled in the art to carry out the various embodiments described herein. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may apply to other embodiments. Accordingly, the claims are not intended to be limited to the embodiments shown herein. All structural and functional equivalent transformations to elements of the various embodiments of this disclosure, which are known or obvious to those skilled in the art, are intended to be covered by the claims.

Claims

1. A device (20) for measuring high voltage on a high voltage node, A power electronic converter comprising a first AC-DC converter (21), a first DC-AC converter (22), and a second AC-DC converter (23), wherein the first AC-DC converter is composed of a rectifier with two diode half-bridges and is connected to the low-voltage arm of a high-voltage divider coupled between the high-voltage node and the device to acquire a voltage measurement signal, the first DC-AC converter is a full-bridge converter with two half-bridges of switching elements connected in series and configured to output a modulated signal of the voltage measurement signal, and the second AC-DC converter includes a rectifier with a diode bridge or is composed of an H-bridge circuit including four switching elements interconnected as an H-bridge circuit and is configured to output a demodulated signal of the voltage measurement signal, A high-frequency transformer (24) comprising a primary coil connected to the output terminal of the first DC-AC converter to receive the modulation signal, and a secondary coil connected to the input terminal of the second AC-DC converter, A controller (25) is configured to supply control signals to the multiple switching elements of the first DC-AC converter in order to control the turn-on sequence of each of the multiple switching elements so that the first DC-AC converter outputs the modulated signal, to calculate signal parameters including phase information and amplitude information of the high voltage on the high voltage node, and to output the calculated signal parameters. Equipped with, The device wherein the controller is configured to calculate the signal parameters based on sensor information received via its input terminal, the sensor information including a voltage across the low-voltage arm and a current through a circuit branch connecting the high-voltage divider and the device.

2. The aforementioned signal parameters are, At least one of the voltage magnitude peak value, RMS value, polarity, phase value, harmonic value, and waveform of the high-voltage signal corresponding to the high voltage on the high-voltage node, The phase offset between the phase of the high-voltage signal and the phase of the voltage measurement signal, and Amplitude deviation between the amplitude of the high-voltage signal and the amplitude of the voltage measurement signal The apparatus (20) according to claim 1, including the apparatus (20).

3. The apparatus (20) according to claim 1 or 2, wherein the apparatus further comprises a second DC-AC converter (27), the input terminal of the second DC-AC converter being connected to the output terminal of the second AC-DC converter, and the second DC-AC converter being configured to output an analog AC signal including phase information and amplitude information of the high voltage on the high voltage node.

4. The apparatus (20) according to any one of claims 1 to 3, wherein the sensor information further includes the temperature of the low-voltage arm and the temperature shift of the device of the power electronic converter.

5. The apparatus (20) according to claim 2, wherein the high-voltage divider is a capacitor voltage divider, and the low-voltage arm is a voltage divider capacitor unit having one terminal connected to ground.

6. The aforementioned controller is based on the following formula: ΔP=k １ *(ΔP C +ΔP R )+k ２ *(ΔP L +ΔP S ) (In the formula, "ΔP" is the phase offset, "ΔP C " is a sub-offset caused by the capacitance of the voltage divider capacitor unit, "ΔP R " is a sub-offset caused by the impedance of the aforementioned device, 「ΔP L 」 is the sub-offset caused by the leakage inductance of the said device, "ΔP S " is a sub-offset caused by the parasitic capacitance of the aforementioned device, "k １ " and "k ２ " is weight, and "k １ " and "k ２ The sum of " and is equal to 1, and "k １ The range of "" is between 0.95 and 0.99, and "k ２ The range is between 0.01 and 0.

05. The apparatus (20) according to claim 5, configured to calculate the phase offset based on the above.

7. The aforementioned controller is based on the following formula: Δa=f １ *(Δa C +Δa R )+f ２ *Δa D (In the formula, "Δa" is the amplitude deviation, "Δa C " is a partial deviation caused by the capacitance of the voltage divider capacitor unit, "Δa R " is a partial deviation caused by the impedance of the device, "Δa D " is a partial deviation caused by the voltage drop of the device, f １ " and "f ２ " is weight, and "f １ " and "f ２ The sum of " and is equal to 1, "f １ The range of "f" is between 0.9 and 0.

95. ２ The range is between 0.05 and 0.

1. The apparatus (20) according to claim 6, configured to calculate the amplitude deviation based on the above.

8. The apparatus (20) according to any one of claims 1 to 7, wherein the turns ratio of the primary coil and the secondary coil is between 1 and 10.

9. The apparatus (20) according to any one of claims 1 to 8, further comprising a filter for removing high-frequency components of the demodulated signal before the demodulated signal is output.

10. The apparatus (20) according to any one of claims 1 to 9, wherein the apparatus is provided in a terminal box that is coupled to the terminal of the low-voltage arm.

11. A system (100) for measuring high voltage on a high voltage node, A high-voltage divider (10) connected to the high-voltage node, comprising a high-voltage arm and a low-voltage arm, A measuring device (20) provided in a terminal box connected to the high-voltage divider, wherein the measuring device is A power electronic converter comprising a first AC-DC converter, a first DC-AC converter, and a second AC-DC converter, wherein the first AC-DC converter is composed of a rectifier comprising two diode half-bridges and is connected to the low-voltage arm to acquire a voltage measurement signal, the first DC-AC converter is a full-bridge converter comprising two half-bridges of switching elements connected in series and configured to output a modulated signal of the voltage measurement signal, and the second AC-DC converter includes a rectifier comprising a diode bridge or is composed of an H-bridge circuit comprising four switching elements interconnected as an H-bridge circuit and is configured to output a demodulated signal of the voltage measurement signal, A high-frequency transformer comprising a primary coil connected to the output terminal of the first DC-AC converter for receiving the modulation signal, and a secondary coil connected to the input terminal of the second AC-DC converter, A controller configured to supply control signals for controlling the multiple switching elements of the first DC-AC converter in order to control the turn-on sequence of each of the multiple switching elements so that the first DC-AC converter outputs the modulated signal, calculate signal parameters including phase information and amplitude information of the high voltage on the high voltage node, and output the calculated signal parameters. The controller is configured to calculate the signal parameters based on sensor information received via its input terminal, wherein the sensor information includes the voltage across the low-voltage arm and the current through the circuit branch connecting the high-voltage divider and the measuring device. A system equipped with these features.

12. The system (100) according to claim 11, wherein at least one of the high-voltage arm and the low-voltage arm is adjusted to match the withstand voltage of the power electron converter.

13. The system (100) according to claim 11 or 12, wherein the high-voltage divider is a capacitor voltage divider, and the low-voltage arm is a voltage divider capacitor unit comprising one or more capacitors.

14. The system (100) according to claim 13, wherein one terminal of the voltage divider capacitor unit is connected to ground, the other terminal is connected to the other voltage divider capacitor unit of the capacitor voltage divider, and the other terminal of the voltage divider capacitor unit is connected via wiring to the input terminal of the first AC-DC converter.

15. A method for measuring high voltage on a high voltage node using a measuring device, The measuring device comprises a power electronic converter, a high-frequency transformer, and a controller. The power electronic converter comprises a first AC-DC converter, a first DC-AC converter, and a second AC-DC converter, wherein the first AC-DC converter is composed of a rectifier with two diode half-bridges and is connected to the low-voltage arm of a high-voltage divider coupled between the high-voltage node and the measuring device, and is configured to acquire the voltage measurement signal of the high voltage on the high-voltage node; the first DC-AC converter is a full-bridge converter with two half-bridges of switching elements connected in series and is configured to output a modulated signal of the voltage measurement signal; and the second AC-DC converter includes a rectifier with a diode bridge or is composed of an H-bridge circuit including four switching elements interconnected as an H-bridge circuit and is configured to output a demodulated signal of the voltage measurement signal. The high-frequency transformer is coupled between the first DC-AC converter and the second AC-DC converter to transmit the modulated signal. The method includes the controller supplying control signals to the plurality of switching elements of the first DC-AC converter in order to control the turn-on sequence of each of the plurality of switching elements so that the first DC-AC converter outputs the modulation signal, The method further comprises the controller calculating signal parameters of phase information and amplitude information of the high voltage on the high voltage node, and outputting the calculated signal parameters, wherein the controller is configured to calculate the signal parameters based on sensor information received via its input terminal, wherein the sensor information includes a voltage across the low voltage arm and a current through a circuit branch connecting the high voltage divider and the measuring device.

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