JP2008008649A - Controller of electromagnetic apparatus and controller of electromagnetic apparatus used in nuclear power plant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller of an electromagnetic apparatus for suppressing noise that arises, and a controller of an electromagnetic apparatus used in a nuclear power plant. <P>SOLUTION: In a control circuit 34a, when a switch is turned on, semiconductor switches 31u and 31v of U and V phases are turned on at a zero-crossing time of a line voltage detected by a line-voltage zero-crossing detection circuit 32uv. Thereafter, a semiconductor switch 31w of a W phase is turned on at a zero-crossing time of an interswitch voltage detected by an interswitch voltage detection circuit 32w. When the switch is turned off, the semiconductor switch 31u of the U phase is turned off at a zero-crossing time of a current zero-crossing detection circuit 33u while the semiconductor switches 31v and 31 of the V and W phases are turned off at a zero-crossing time of a current zero-crossing detection circuit 33v. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electromagnetic device control device and an electromagnetic device control device used in a nuclear power plant, and more particularly to an electromagnetic device suitable for controlling an electromagnetic device or the like installed in a nuclear reactor containment vessel of a nuclear power plant. The present invention relates to a control device.

  The nuclear power plant nuclear instrumentation system is composed of a neutron source region monitor, an intermediate region monitor, and an output region monitor in order to be able to measure from the activation state of the nuclear reactor starting fission to the full output. Recently, an activation region neutron monitor in which a neutron source region monitor and an intermediate region monitor are integrated has been put into practical use. A neutron source area monitor, intermediate area monitor, or start-up area neutron monitor requires a preamplifier to amplify very weak signals from a neutron detector installed in the reactor, for example, a pulse current in the order of μA. Yes, this preamplifier is installed outside the reactor containment vessel from the viewpoint of radiation resistance. A nuclear instrumentation system that monitors neutrons is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-149378.

JP 2003-149378 A

  In recent years, a phenomenon in which noise has been superimposed on a detection signal of a neutron detector in a nuclear power plant, which has not been seen in the past, has often been observed. The detection signal of the neutron detector is an extremely important signal that reflects the state of the nuclear reactor. If noise is added to the signal, it may hinder proper control of the nuclear power plant.

  The objective of this invention is providing the control apparatus of the electromagnetic device which can suppress the noise to generate | occur | produce, and the control apparatus of the electromagnetic device used for a nuclear power plant.

  The present inventors diligently studied the cause of noise included in the detection signal of the neutron detector. As a result, in response to recent advances in digitization technology, various digital devices have been introduced into nuclear power plants to improve functions and performance, the equipment environment of nuclear power plants has changed, and nuclear reactors. The drive signal for operating and controlling various electromagnetic devices such as motors, pumps, and solenoid valves installed in the reactor containment vessel for the control and protection of the reactor is related to the noise superimposed on the neutron detection signal. I found out.

  The present invention specifies the cause of the noise that appears in the neutron detection signal of the nuclear instrumentation system, and as a countermeasure, it prevents electromagnetic noise from being generated, especially when driving three-phase electromagnetic equipment that is often used in plants. is there.

(1) In order to achieve the above object, according to the present invention, there is provided a control device for an electromagnetic device that performs on / off control of power of a three-phase power source supplied to the electromagnetic device, and a semiconductor switch provided in each phase, at least between the lines The voltage detection means for detecting the voltage or the voltage between the switches and the voltage value detected by the voltage detection means in response to an external switch-on command are used to turn on a predetermined two-phase semiconductor switch at a predetermined timing. Thereafter, a control means for turning on the one-phase semiconductor switch remaining in a predetermined procedure is provided.
With this configuration, generated noise can be suppressed.

  (2) In the above (1), preferably, it further comprises a load current detecting means, and the control means is a switch-off command from the outside, and the load current detected by the load current detecting means is a predetermined value. At this time, the current detection phase semiconductor switch is turned off, and then the remaining two-phase semiconductor switch is turned off by a predetermined procedure.

  (3) In the above (2), preferably, the voltage detection means is a line voltage detection means and an inter-switch voltage detection means, and includes two load current detection means as the load current detection means, The control means turns on the two-phase semiconductor switch at the zero cross timing of the line voltage detected by the line voltage detection means in response to a switch-on command from the outside, and then further detected by the voltage detection means between the switches. The remaining one-phase semiconductor switch is turned on at the zero-cross timing of the voltage between the switches, and the first switch is detected at the zero-cross timing of the first load current detecting means by the switch-off command from the outside. The current detection phase semiconductor switch is turned off, and then the zero cross tie of the second load current detection means out of the two load current detection means It is obtained so as to turn off the semiconductor switch remains in the ring two phases.

  (4) In the above (2), preferably, the voltage detection means is a line voltage detection means, and the control means is a line detected by the line voltage detection means in response to an external switch-on command. Turn on the two-phase semiconductor switch detected at the zero-crossing timing of the inter-voltage, and then wait for a time corresponding to the 90 ° phase of the power supply frequency with a timer, turn on the remaining one-phase semiconductor switch, In response to the switch-off command, the semiconductor switch of the current detection phase is turned off at the zero cross timing of the load current detected by the load current detection means, and after that, the timer waits for a time corresponding to the 90 ° phase of the power supply frequency, and the remaining two The semiconductor switch of the phase is turned off.

  (5) In the above (4), preferably, the line voltage detecting means is provided over two phases, and the load current detecting means is provided in another phase.

  (6) In the above (2), preferably, the voltage detecting means is a line voltage detecting means, and the control means is a switch detected by the line voltage detecting means in response to an external switch-on command. The timer is operated at the zero cross timing of the inter-voltage value, waits 90 degrees in terms of the power frequency, turns on the predetermined two-phase semiconductor switch, turns on the remaining one-phase semiconductor switch at the next zero cross, With the switch-off command from, the semiconductor switch of the current detection phase is turned off at the zero cross timing of the load current detected by the load current detection means, and then the timer waits for a time corresponding to the 90 ° phase of the power supply frequency, and remains The two-phase semiconductor switch is turned off.

  (7) In the above (5), preferably, the voltage detection means and the load current detection means are provided in the same phase.

(8) Moreover, in order to achieve the said objective, this invention installed the reactor pressure vessel and the electromagnetic device in the reactor containment vessel, and was accommodated in the instrumentation pipe inserted in the said reactor pressure vessel. A control device for an electromagnetic device used in a nuclear power plant in which an output of a neutron detector is input to a preamplifier installed outside the reactor containment vessel by a signal cable, and installed outside the reactor containment vessel A power cable that is laid between the power supply and the electromagnetic device, and that supplies power from the power source to the electromagnetic device; The power of the three-phase power supply is controlled on and off. The semiconductor switch provided in each phase, the voltage detection means for detecting at least the line voltage or the voltage between the switches, and the external switch Using a voltage value detected by the voltage detection means in a thioon command, turn on a predetermined two-phase semiconductor switch at a predetermined timing, and then switch on the remaining one-phase semiconductor switch in a predetermined procedure. Control means for turning on is provided.
With this configuration, generated noise can be suppressed.

  (9) In the above (8), preferably, load current detecting means is provided, and the control means is a switch-off command from the outside, and the load current detected by the load current detecting means becomes a predetermined value. At this time, the semiconductor switch for the current detection phase is turned off, and then the remaining two-phase semiconductor switch is turned off by a predetermined procedure.

  According to the present invention, generated noise can be suppressed.

Hereinafter, the configuration and operation of the control device for an electromagnetic device according to the first embodiment of the present invention will be described with reference to FIGS.
First, the overall configuration of a nuclear power plant to which the control apparatus for electromagnetic equipment according to the present embodiment is applied will be described with reference to FIG.
FIG. 1 is a system configuration diagram showing the overall configuration of a nuclear power plant to which an electromagnetic device control apparatus according to a first embodiment of the present invention is applied.

  The neutron detectors 3A and 3B are accommodated in instrumentation tubes 2A and 2B inserted into the reactor pressure vessel 1. There are three types of neutron detectors 3A and 3B: a neutron source region monitor, an intermediate region monitor, and a start-up region neutron monitor, and a weak current is generated by the ionizing action of thermal neutrons in the reactor. This weak current signal is amplified by preamplifiers 8A and 8B installed outside the reactor containment vessel 5, and a reactor output signal is obtained. The neutron detectors 3A and 3B and the preamplifiers 8A and 8B are connected by coaxial cables (detector cables) 4A and 4B. Connectors 41A and 41B are attached to the lower ends of the instrumentation tubes 2A and 2B, and the coaxial cables 4A and 4B can be removed during maintenance. The coaxial cables 4A and 4B pass through the penetrations of the cable containment 6A and 6B passing through the reactor containment vessel 5, that is, through the through holes of the reactor containment vessel 5 for passing the cables through the inside and outside of the reactor containment vessel 5, respectively. 9 are connected to preamplifiers 8A and 8B installed in the inside. These coaxial cables 4A and 4B are laid in the thick steel conduits 7A and 7B, and the output signals of the preamplifiers 8A and 8B are coaxial cables (in the figure) installed in the thick steel conduits 7A and 7B. (Not shown) is input to the neutron monitoring devices 11A and 11B in the control building 10.

  A large number of three-phase electromagnetic devices 20 for controlling and protecting the reactor are installed in the reactor containment vessel 5, and these electromagnetic devices 20 supply power from a three-phase AC power source 19 via a power cable 13. Driven by. Examples of the three-phase electromagnetic device 20 include a motor, a pump, a solenoid valve, and an electric valve. The power cable 13 passes through the cable penetration 6C and is connected to the three-phase power switch device 30. In the figure, the power cable 13 is laid in the thick steel conduit 7C, but this is not necessarily the case, and the power cable 13 is laid in a flexible conduit whose metal part is thinner than the thick steel conduit 7C. There is no thick steel conduit 7C. Conversely, all the power cables may be contained in the thick steel conduit 7C or the flexible conduit.

  The three-phase power switch device 30 is turned on / off by a drive command given by the operation switch 17 on the operation panel 18 in the control building 10, and the power supply from the power source 19 to the electromagnetic device 20 is controlled. The three-phase power switch device 30 may be installed in the reactor building 9 or in the control building 10.

  This embodiment is characterized in that the power supply from the power source 19 to the electromagnetic device 20 is controlled by turning the three-phase power switch device 30 on and off. A specific configuration of the three-phase power switch device 30 will be described later with reference to FIG.

  Here, the mechanism of noise generation clarified by the present inventors will be briefly described. In a conventional nuclear power plant, instead of the three-phase power switch device 30, a switch device including a relay or a contactor is generally used.

  As described above, in recent years, digitalization technology has advanced, and various digital devices have been introduced into nuclear power plants to improve the function and performance of the plant. This digital device radiates electromagnetic noise from the device itself or from a cable connected to the device. As a large number of digital devices are installed in nuclear power plants, the background level of electromagnetic noise is increasing. For this reason, the level of background noise induced in the detector cables 4A and 4B is also increased, and electromagnetic noise radiated from the power cable 13 is induced in the detector cables 4A and 4B in such an environment. The present inventors have found that the possibility of instruction fluctuation of the neutron monitoring devices 11A and 11B is increasing. The configuration of driving an electromagnetic device such as a pump via a power cable 13 installed in the reactor containment vessel is not different from the conventional configuration, and conventionally, noise is generated in the detection signal of the neutron detector by the drive signal of the electromagnetic device. I never did. Since the background level of electromagnetic noise has increased as a result of the digitization of nuclear power plants, weak electromagnetic noise radiated from electromagnetic equipment such as power cables or pumps in the reactor containment vessel has become a neutron detection signal. It began to cause fluctuations.

  Here, when an AC voltage is applied to an electromagnetic device, when the contactor, which is a switching element, is turned on or turned off, it is repeatedly turned on and off for a short time due to mechanical chattering of the contact point. Occurs. This phenomenon is the same when a relay is used as the switching element. This noise current is transmitted through the power cable 13, and electromagnetic noise is radiated from the power cable 13 into the space in the reactor containment vessel 5 due to this noise current. The frequency of this noise current is a high-frequency electromagnetic noise determined by the inductance and resistance of the wiring in the contactor part, the stray capacitance between contactor contacts, and the like, and as a result of actual measurement, it was about 100 KHz to several tens of MHz. Even when all the power cables 13 are laid in the thick steel conduit 7C, high-frequency electromagnetic noise is radiated into the space from the frame of the electromagnetic device. When the electromagnetic device is a pump or a motor, the high-frequency electromagnetic noise is radiated from the frame through a stray capacitance between the winding and the frame.

  On the other hand, the detector cables 4A and 4B are not all contained in the thick steel conduits 7A and 7B, and the detector cables 4A and 4B can be detached at the connectors 41A and 41B during maintenance. For this reason, the detector cables 4A and 4B remain coaxial cables in the lower part of the reactor pressure vessel 1. For this reason, electromagnetic noise radiated from the power cable 13 and the frame of the pump 12 is induced to the detector cables 4A and 4B. The preamplifiers 8A and 8B amplify a pulse current on the order of μA, but the amplification degree is very high from 1000 times to 10,000 times, and the frequency range is from several hundred KHz to several tens MHz, and high gain and wide bandwidth It has become. Since the frequency of the electromagnetic noise induced in the detector cables 4A and 4B is about 100 KHz to several tens of MHz, the electromagnetic noise is amplified by a preamplifier and input to the neutron monitoring devices 11A and 11B. become. As a result, it was found that the neutron monitoring devices 11A and 11B may generate an instruction variation when the pump 12 is driven or stopped.

  The induction of electromagnetic noise is mainly common mode noise, but there is also normal mode noise due to the difference in induction effect on the core wires and shield wires of the detector cables 4A and 4B. As suppression of common mode noise, as shown in Japanese Patent Laid-Open No. 7-84088, it has been studied to install a common mode choke coil in the input stage of the preamplifiers 8A and 8B. Although it is possible to suppress noise, it is different on a case-by-case basis whether the effect is sufficient to completely eliminate the effects on nuclear instrumentation when the generated noise is large. Also, normal mode noise cannot be suppressed.

  On the other hand, in the nuclear power plant according to the present embodiment, MOSFETs are used as the switching elements of the three-phase power switch device 30, and the three-phase power switch device 30 is installed in the reactor building 9. The three-phase power switch device 30 uses a semiconductor element as an opening / closing element to drive (switch on / off) an electromagnetic device (for example, a pump, a motor, an electric valve, an electromagnetic valve, etc.). The noise current generated at the time of switching on or off is drastically reduced from that of a relay or contactor having a conventional mechanical contact structure, and radiation due to the noise current transmitted through the power cable 13 of the electromagnetic device in the reactor containment vessel 5 Electromagnetic noise can sufficiently suppress noise induction to the detector cables 4A and 4B of the nuclear instrumentation. Furthermore, noise generation is further suppressed by controlling the opening / closing timing of the opening / closing element.

Next, the circuit configuration of the control device for the electromagnetic device according to the present embodiment will be described with reference to FIGS.
FIG. 2 is a block diagram showing the configuration of the electromagnetic device control apparatus according to the first embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts. 3 to 6 are operation explanatory diagrams of the control device for the electromagnetic device according to the first embodiment of the present invention.

  The three-phase power switch device 30 includes MOSFETs 31u, 31v, and 31w as semiconductor switches that open and close each of the three phases. On / off of the MOSFETs 31u, 31v, 31w is controlled by the control circuit 34a. Furthermore, a line voltage zero-cross detection circuit 32uv and an inter-switch voltage zero-cross circuit 32w are provided as voltage zero-cross detection circuits, and a current zero-cross detection circuit 33u provided in the U-phase and a current zero-cross detection circuit 33u provided in the V-phase. The current zero cross detection circuit 33v is provided. The control circuit 34a controls the on / off timing of the three MOSFET switches 31u, 31v, 31w based on the detection results of the four zero cross detection circuits.

  The three-phase power switch device 30 is designed not to generate a noise current in principle when switching the switching element on or off, and when the AC voltage applied to the electromagnetic device crosses the zero point, the MOSFETs 31u, 31v. , 31w are turned on, and the three-phase power supply is turned off when the AC current is zero-crossed. However, the on / off timing is not implemented at the same time for the three phases but separately as will be described later.

  FIG. 3 shows the waveform of each phase of the line voltage of the three-phase power source. Vu, Vv, and Vw are voltage waveforms between the lines. As can be seen from the figure, there is no timing for the voltage to zero-cross at the same time for all three lines, so it can be seen that some device is required to turn on the power supply without causing a sudden change in current.

  4 to 6 are diagrams for explaining the operation of the three-phase power switch device 30 of FIG. 2, and are the results calculated by the circuit simulator. This is a case where the power supply frequency is 50 Hz, and the absolute time of switching also changes at other frequencies, but the idea is the same. This calculation result is for a resistive load. When the power is turned on, the phase of the applied voltage is important, and the phase of the applied voltage does not depend on the load. When the switch is off, the current phase is monitored to determine the switch timing. However, since the loads in each phase are considered to have the same impedance, the phase difference of the current between the phases is the same as in the case of a resistive load. That is, the simulation result can be used even when the load is an electromagnetic device including an inductance.

  FIG. 4 shows a voltage detection waveform Vu of the line voltage zero-cross detection circuit 32uv and a detection waveform Vsw of the inter-switch voltage zero-cross circuit 32w. FIG. 5 shows the current waveforms iu, iv, iw of each phase at this time.

  The control circuit 34a turns on the U and V phase switches 31u and 31v at the zero cross point (about 18.4 ms) of the line voltage Vu detected by the line voltage zero cross detection circuit 32uv. Thus, it can be seen that the currents iu and iv start to flow from zero current, change in a substantially sinusoidal shape, and no steep current change occurs.

  Next, the control circuit 34a turns on the switch 31w of the phase that is not turned on at the time (about 23.4 ms) at which the inter-switch voltage Vsw detected by the inter-switch voltage zero-cross circuit 32w is zero-crossed. Thus, it can be seen that the current iw changes from zero in a sine wave shape and no sudden change in current occurs.

  As described above, at first, the voltage between the U and V phase two lines is turned on at zero timing, so that the current flowing in accordance with the applied voltage between the two lines also changes from zero to a sine wave, resulting in a steep current change. Does not occur. Next, since the switch was turned on when the voltage between the remaining phase switches was zero, the current increased in a sine wave shape without a sharp current change. That is, the circuit configuration shown in FIG. 2 can be switched without causing a steep current change, that is, with almost no noise when the three-phase power supply is turned on.

  As the current zero cross detection circuit, a current zero cross detection circuit 33u provided in the U phase and a current zero cross detection circuit 33v provided in the V phase are provided. The control circuit 34a controls the on / off timing of the three MOSFET switches 31u, 31v, 31w based on the detection results of the four zero cross detection circuits.

  FIG. 6 shows a current waveform for explaining power-off. The current of each phase is iu, iv, iw, respectively.

  The control circuit 34a turns off the U-phase switch 31u at the time (30 ms) when the U-phase current detected by the current zero-cross detection circuit 33u zero-crosses. The control circuit 34a turns off the V and W phase switches 31v and 31w at the time (35 ms) when the V phase current detected by the current zero cross detection circuit 33v zero crosses. It can be seen that a steep current change does not occur because the switch is turned off at the timing when the current is zero.

  In FIG. 2, the line voltage zero cross detection circuit 32uv and the switch voltage zero cross circuit 32w can be realized by a voltage transformer and a comparator, and the phase current zero cross detectors 33u and 33v can be realized by a current probe and a comparator. Yes, the control circuit 34a can be realized by a logic circuit that ANDs the open / close command of the operation switch 17 and the zero-cross detection timing. Although not shown, semiconductor suppression MOSFETs 31u, 31v, 31w are connected with voltage suppression diodes for protection.

  As described above, in the present embodiment, when the three-phase power supply is on, the two phases are turned on first after detecting the voltage zero cross point, and the remaining one phase is turned on next. In the case of three-phase power off, the first phase is turned off when the current zero cross point is detected, and the remaining two phases are then turned off. Thus, it is characterized in that it is turned on and off in two steps.

  According to this embodiment, since the generation timing of the high-frequency noise can be greatly suppressed by controlling the operation timing of the switching element that controls the on / off of the driving of the three-phase electromagnetic device so as not to cause a sudden current change, It is possible to sufficiently suppress the influence of noise on the mounting system and reduce the possibility of instruction fluctuation. Therefore, in the nuclear power plant, the neutron level of the nuclear reactor can be accurately measured.

Next, the circuit configuration of the electromagnetic device control apparatus according to the second embodiment of the present invention will be described with reference to FIG. In addition, the whole structure of the nuclear power plant to which the control apparatus for electromagnetic equipment according to the present embodiment is applied is the same as that shown in FIG.
FIG. 7 is a block diagram showing the configuration of the control device for an electromagnetic device according to the second embodiment of the present invention. 1 and 2 indicate the same parts.

  The three-phase power switch device 30A is different from the configuration of FIG. 2 in that one zero-cross detection circuit 32uv and one current zero-cross detection circuit 33w are provided as zero-cross detection circuits.

  When the three-phase power supply is turned on by the operation switch 17, the control circuit 34b detects the voltage zero cross by the line voltage zero cross detection circuit 32uv, turns on the U and V phase switches 31u and 31v, and then the control circuit. 34b waits for a time corresponding to a phase of the power supply frequency of 90 ° (5 ms at the power supply frequency 50 Hz, 4.17 ms at 60 Hz) by the built-in timer, and turns on the W-phase switch 31 w. It has been confirmed through circuit simulation that after two-phase switch-on, a switch timing without a sudden change in current occurs after 5 ms at 90 °, that is, 50 Hz.

  When the three-phase power supply is turned off by the operation switch 17, the control circuit 34b detects the current zero cross by the phase current zero-cross detection circuit 33w, turns off the W-phase switch 31w, and then the control circuit 34b The timer waits for a time corresponding to the phase of the power supply frequency of 90 ° (power supply frequency 50 Hz, 5 ms, 60 Hz, 4.17 ms), and then the U and V phase switches 31 u and 31 v are turned off. It is clear from the waveform of FIG. 6 that the timing of the second switching can be determined by the timer.

  As described above, the first switching operation of the power on / off can be determined by referring to the detection result of the zero cross detector and the second switching can be determined by the timer. In this way, the detection circuit can be simplified. In this case, the control circuit 34b needs to incorporate a timer, but the circuit is not particularly complicated.

  In FIG. 7, the line voltage is detected in the U and V phases and the current is detected in the W phase. However, if only the function is considered, the voltage is detected in the U and V phases, and the current is detected in the U phase. May be. The reason why the voltage detection phase and the current detection phase in FIG. 7 are separated is to enable the control circuit to turn on and off the switches 31u and 31v at the same time whether the power is on or off. From the viewpoint of the control circuit, the groups 31u and 31v, 31w and the switch can be handled as two, and the control circuit can be simplified.

  According to this embodiment, since the generation timing of the high-frequency noise can be greatly suppressed by controlling the operation timing of the switching element that controls the on / off of the driving of the three-phase electromagnetic device so as not to cause a sudden current change, It is possible to sufficiently suppress the influence of noise on the mounting system and reduce the possibility of instruction fluctuation. Therefore, in the nuclear power plant, the neutron level of the nuclear reactor can be accurately measured. In addition, the control circuit can be simplified.

  Next, the circuit configuration of the electromagnetic device control apparatus according to the third embodiment of the present invention will be described with reference to FIGS. In addition, the whole structure of the nuclear power plant to which the control apparatus for electromagnetic equipment according to the present embodiment is applied is the same as that shown in FIG.

  FIG. 8 is a block diagram showing the configuration of the control device for an electromagnetic device according to the second embodiment of the present invention. 1 and 2 indicate the same parts. 9 and 10 are explanatory diagrams of the operation of the control device for an electromagnetic device according to the third embodiment of the present invention.

  A three-phase power switch device 30B shown in FIG. 8 includes semiconductor switch MOSFETs 31u, 31v, 31w, an inter-switch voltage zero-cross detection circuit 32u, a U-phase current zero-cross detection circuit 33u, and a control circuit 34c.

  FIG. 9 shows a waveform of the inter-switch voltage Vsw. When the three-phase power supply is turned on by the operation switch 17, when the zero cross point is detected by Vsw detected by the inter-switch voltage zero cross detection circuit 32u, the control circuit 34c further controls the phase 90 ° ( After waiting for 5 ms), the V and W phase switches 31v and 31w are turned on, and the U phase switch 31u is turned on at the next voltage zero cross. As shown in FIG. 10, it can be confirmed that there is no steep change in the current change in this case.

  When the three-phase power supply is turned off by the operation switch 17, the control circuit 34c turns off the U-phase switch 31u when the current zero cross is detected by the phase current zero-cross detection circuit 33u, and then the built-in timer. After waiting for a time corresponding to 90 ° of the phase of the power supply frequency (5 ms at the power supply frequency 50 Hz, 4.17 ms at 60 Hz), the V and W phase switches 31v and 31w are turned off.

  The reason why the voltage detection phase and the current detection phase in FIG. 8 are the same is to allow the control circuit to turn on and off the switches 31v and 31w at the same time whether the power is on or off. From the viewpoint of the control circuit, 31v and 31w groups, 31u and switches can be handled as two, and the control circuit can be simplified.

  According to this embodiment, since the generation timing of the high-frequency noise can be greatly suppressed by controlling the operation timing of the switching element that controls the on / off of the driving of the three-phase electromagnetic device so as not to cause a sudden current change, It is possible to sufficiently suppress the influence of noise on the mounting system and reduce the possibility of instruction fluctuation. Therefore, in the nuclear power plant, the neutron level of the nuclear reactor can be accurately measured. In addition, the control circuit can be simplified.

In each of the above embodiments, a MOSFET is used as a semiconductor switch, but other semiconductor elements IGBT, transistors, thyristors, etc. can of course be used. In the case of a thyristor, if one having natural commutation characteristics is used, a current zero cross circuit becomes unnecessary, which can be further simplified.

1 is a system configuration diagram showing an overall configuration of a nuclear power plant to which an electromagnetic device control apparatus according to a first embodiment of the present invention is applied. It is a block diagram which shows the structure of the control apparatus of the electromagnetic device by the 1st Embodiment of this invention. It is operation | movement explanatory drawing of the control apparatus of the electromagnetic device by the 1st Embodiment of this invention. It is operation | movement explanatory drawing of the control apparatus of the electromagnetic device by the 1st Embodiment of this invention. It is operation | movement explanatory drawing of the control apparatus of the electromagnetic device by the 1st Embodiment of this invention. It is operation | movement explanatory drawing of the control apparatus of the electromagnetic device by the 1st Embodiment of this invention. It is a block diagram which shows the structure of the control apparatus of the electromagnetic device by the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the control apparatus of the electromagnetic device by the 3rd Embodiment of this invention. It is operation | movement explanatory drawing of the control apparatus of the electromagnetic device by the 3rd Embodiment of this invention. It is operation | movement explanatory drawing of the control apparatus of the electromagnetic device by the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Reactor pressure vessel 2A, 2B ... Instrumentation tube 3A, 3B ... Neutron detector 4A, 4B ... Detector cable 5 ... Reactor containment vessel 6A, 6B, 6C ... Cable penetration 7A, 7B, 7C ... Thick steel wire Tube 8A, 8B ... Preamplifier 9 ... Reactor building 11A, 11B ... Neutron monitoring device 13 ... Power cable 19 ... Three-phase power source 20 ... Three-phase electromagnetic device 30 ... Three-phase power switch device 31 ... Semiconductor switch 32 ... Voltage zero cross Detection circuit 33 ... Current zero cross detection circuit 34 ... Control circuit

Claims (9)

In a control device for an electromagnetic device that performs on / off control of the power of a three-phase power source supplied to the electromagnetic device
A semiconductor switch provided for each phase;
Voltage detection means for detecting at least the line voltage or the switch voltage; and
Using a voltage value detected by the voltage detection means in response to an external switch-on command, a predetermined two-phase semiconductor switch is turned on at a predetermined timing, and then the one-phase remaining in a predetermined procedure A control device for electromagnetic equipment, comprising: a control means for turning on the semiconductor switch. The control apparatus for an electromagnetic device according to claim 1, further comprising:
A load current detecting means;
The control means turns off the semiconductor switch of the current detection phase when the load current detected by the load current detection means reaches a predetermined value by an external switch-off command, and then a predetermined procedure The apparatus for controlling an electromagnetic device is characterized in that the two-phase semiconductor switch remaining in the step is turned off. In the control apparatus of the electromagnetic device according to claim 2,
The voltage detection means is a line voltage detection means and a switch voltage detection means,
The load current detection means comprises two load current detection means,
The control means turns on the two-phase semiconductor switch at the zero cross timing of the line voltage detected by the line voltage detection means in response to a switch-on command from the outside, and then further detects by the voltage detection means between the switches. Turn on the remaining one-phase semiconductor switch at the zero cross timing of the voltage between the switches
A switch-off command from the outside turns off the semiconductor switch of the first current detection phase at the zero-cross timing of the first load current detection means out of the two load current detection means, and then the two load current detection means Among them, the two-phase semiconductor switch remaining at the zero cross timing of the second load current detecting means is turned off. In the control apparatus of the electromagnetic device according to claim 2,
The voltage detection means is a line voltage detection means,
The control means turns on the two-phase semiconductor switch detected at the zero-cross timing of the line voltage detected by the line voltage detection means in response to a switch-on command from the outside. Wait for a time corresponding to 90 ° phase, turn on the remaining one-phase semiconductor switch,
With the switch-off command from the outside, the semiconductor switch of the current detection phase is turned off at the zero cross timing of the load current detected by the load current detection means, and then waits for a time corresponding to the 90 ° phase of the power supply frequency with a timer, A control device for an electromagnetic device, wherein the remaining two-phase semiconductor switch is turned off. The control apparatus for an electromagnetic device according to claim 4,
The line voltage detection means is provided across two phases,
The control apparatus for an electromagnetic device, wherein the load current detection means is provided in another phase. In the control apparatus of the electromagnetic device according to claim 2,
The voltage detection means is a line voltage detection means,
The control means operates in accordance with a switch-on command from the outside, operates a timer at the zero-cross timing of the voltage value between the switches detected by the line voltage detection means, waits 90 degrees in terms of the phase of the power supply frequency, and determines the predetermined two Turn on the phase semiconductor switch, turn on the remaining one-phase semiconductor switch at the next zero cross,
With the switch-off command from the outside, the semiconductor switch of the current detection phase is turned off at the zero cross timing of the load current detected by the load current detection means, and then waits for a time corresponding to the 90 ° phase of the power supply frequency with a timer, A control device for an electromagnetic device, wherein the remaining two-phase semiconductor switch is turned off. The control apparatus for an electromagnetic device according to claim 5,
The control apparatus for an electromagnetic device, wherein the voltage detection means and the load current detection means are provided in the same phase. A reactor pressure vessel and electromagnetic equipment are installed in the reactor containment vessel.
Electromagnetics used in a nuclear power plant in which the output of a neutron detector housed in an instrumentation tube inserted into the reactor pressure vessel is input to a preamplifier installed outside the reactor containment vessel by a signal cable A device control device,
A power cable installed between a power source installed outside the reactor containment vessel and the electromagnetic device, and supplying power from the power source to the electromagnetic device;
On-off control of the power of the three-phase power source installed in the middle of the power cable and supplied to the electromagnetic device arranged outside the containment vessel,
A semiconductor switch provided for each phase;
Voltage detection means for detecting at least the line voltage or the switch voltage; and
Using a voltage value detected by the voltage detection means in response to an external switch-on command, a predetermined two-phase semiconductor switch is turned on at a predetermined timing, and then the one-phase remaining in a predetermined procedure The control apparatus of the electromagnetic equipment used for the nuclear power plant characterized by including the control means which turns ON the semiconductor switch of. The control apparatus for an electromagnetic device according to claim 8, further comprising:
A load current detecting means;
The control means turns off the semiconductor switch of the current detection phase when the load current detected by the load current detection means reaches a predetermined value by an external switch-off command, and then a predetermined procedure The control apparatus of the electromagnetic equipment used for the nuclear power plant characterized by turning off the two-phase semiconductor switch remaining in step 1.

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