JPS60218097A - Static type variable frequency power supply device for driving recirculating pump of cooling material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Technical field of invention) The present invention relates to a boiling water reactor (hereinafter abbreviated as BWR).

) The stationary variable frequency power supply device that drives the coolant recirculation pump with the output of the SiRisk inverter is used to prevent nuclear reactor accidents that are expected to occur when the output frequency suddenly changes due to control system failure, etc. The present invention relates to a static variable frequency power supply device that can prevent such problems.

[Technical background of the invention and its problems] As is well known,
In BWR, a method of controlling the reactor coolant recirculation flow rate is adopted as a means of controlling the plant output. Specifically, this is accomplished by driving the coolant recirculation pump with a variable frequency power supply and varying the output frequency of this power supply.

By the way, as a variable frequency power supply measure, the M-G set (motor/
generator set) is used. However, in recent years, there has been a trend toward the use of static variable frequency power supplies that are superior in terms of efficiency and responsiveness. This stationary variable frequency power supply is a DC-AC converter, that is, an inverter, mainly composed of a conversion element formed by bridge-connecting thyristors, and the desired frequency can be achieved by controlling the firing phase of each thyristor. It is configured to provide AC output.

However, even such a stationary variable frequency power supply device has the following problems. That is, M-G
In the case of a set, its output frequency will never exceed the synchronous rotational speed of the drive motor. Furthermore, the output frequency does not change suddenly due to the inertia of the rotating body. However, in the case of a static variable frequency power supply, if a failure occurs in the control system, etc., the output frequency may change suddenly. A sudden change in the material recirculation flow rate can have a significant impact not only on the reactor but also on related equipment. For example, a sudden increase in the coolant recirculation flow rate can cause a sudden increase in reactor power, which can potentially damage the reactor core. In addition, if the coolant recirculation flow rate suddenly decreases, heat removal from the core will deteriorate, which can also damage the core, and in the worst case, lead to the release of radioactive materials from the core to the environment. In this way, when using a stationary variable frequency power supply as a drive power source for a BWR's coolant recirculation pump, it is necessary to take measures against failures in the control system, etc., and it is hoped that these measures will be implemented as soon as possible. The reality is that there are.

[Purpose of the invention]

The present invention was made in view of the above circumstances, and its purpose is to provide coolant regeneration that can prevent BWR accidents even if a failure occurs in the l1jiill system, etc. An object of the present invention is to provide a stationary variable frequency power supply device for driving a circulation pump.

(Summary of the Invention) The present invention provides a stationary variable frequency power supply device in which a coolant recirculation pump of a boiling water nuclear reactor is driven by the output of a silice inverter. a frequency change rate detector which detects the output frequency change rate of the inverter; and when the output of the frequency change rate detector exceeds a predetermined value or the output of the frequency detector The present invention is characterized by comprising means for stopping the operation of the inverter when the value exceeds a predetermined value.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of a power supply device according to an embodiment of the present invention.

In the figure, reference numeral 1 denotes a station AC bus, and this bus 1 is connected to the primary winding of a transformer 3 via a circuit breaker 2. Both ends of the secondary winding of the transformer 3 are connected to an AC input end of a rectifier 4. A DC output end of the rectifier 4 is connected to a DC input end of the inverter body 6 via a DC reactor 5. The inverter main body 6 is formed, for example, by three-phase bridge-connected thyristors, and its AC output terminal is connected to an electric motor 118, which is a power source for a BWR coolant recirculation pump (not shown), through a transformer 7. It is connected to the.

On the other hand, a control device 9 is provided to control conduction of each thyristor of the inverter main body 6.1. This control device 9 is configured as follows. That is, a speed command signal S given from a speed command system (not shown) is transmitted to the command converter 1.
0 to convert it into a frequency signal, and this signal is introduced into the V/F converter 11 where it is converted into a pulse train with a frequency six times the output frequency of the inverter main body 6. And the above V/F conversion! The output signal of 111 is sent to ring counter 12.
is introduced into the inverter main body 6 and distributed into pulse signals that fire each thyristor of the inverter main body 6, and these distributed pulse signals are sent to the inverter main body via a gate block circuit 13 that performs a block operation when the stop command signal X is introduced. A pulse amplifier 14 generates a gate signal for each thyristor of 6.
We are planning to introduce it to Further, the output voltage of the transformer 7 is introduced into a frequency detector 16 and a frequency change rate detector 17 via a voltage transformer 15. The output signals of both detectors 16 and 17 are then introduced into a comparator 18, respectively. The comparator 18 sends out a stop command signal X when the output of the frequency detector 16 exceeds a predetermined value or when the output signal of the frequency change rate detector 17 exceeds a predetermined value. It is configured as follows.

With such a configuration, if the speed command signal S is abnormal or the command converter 10 or V/F converter 11 breaks down, and the output frequency of the inverter main body 6 increases or suddenly changes, This change immediately causes frequency detector 1
6 and the frequency change rate detector 17.

Comparator T8 then compares these signals with a predetermined set value, and outputs a stop command signal X when either one exceeds the set value. When the stop command signal @X is sent in this way, the gate block circuit 13 performs a blocking operation and stops supplying the pulse signal to the pulse amplifier 14. Therefore, the operation of the inverter main body 6 is stopped, and the input supply to the electric motor 8 is cut off. Therefore, the safety of the BWR is ensured.

FIG. 2 shows a power supply device according to another embodiment of the present invention, in which the same parts as in FIG. 1 are designated by the same reference numerals. Therefore, the explanation of the overlapping parts will be omitted.

This embodiment differs from the previous embodiment in that the frequency detector 1
6a, the method of introducing the input signal to the frequency change rate detector 17a, and the use of the stop command signal X output from the comparator 18 as the trip command signal for the circuit breaker 2.

That is, the period of the pulse train signal sent from the ring converter 12 and the period of the output frequency of the inverter main body 6 are in a corresponding relationship. Therefore, in this embodiment, the output of the ring counter 12 is introduced into the frequency detector 16a and the frequency change rate detector 17a to equivalently detect the output frequency and output frequency change rate of the inverter main body 6. .

Then, the gate pulse supply to the inverter main body 6 is stopped.
Instead, the circuit breaker 2 is tripped by the output of the comparator 18.

Even with this configuration, the same effects as in the embodiment described above can be obtained.

〔Effect of the invention〕

When a stationary variable frequency power supply is used as the power supply for driving the coolant recirculation pump, the coolant recirculation pump drive can prevent the rise and sudden changes in the core flow rate, which would be a concern in the event of a control system failure. It is possible to provide a stationary variable frequency power supply device for use.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a static variable frequency power supply device for driving a coolant recirculation pump according to an embodiment of the present invention, and FIG. 2 is a block diagram of a stationary variable frequency power supply device for driving a coolant recirculation pump according to another embodiment of the present invention. FIG. 2 is a professional configuration diagram of a stationary variable frequency power supply device. 6... Inverter main body, 8... Electric motor, 9.9a.
... Control] device, 13... Gate block circuit, 16
．． 16a...Frequency detector, 17.17a...Frequency change rate detector, 18...Comparator. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2

Claims (1)

[Claims] (1) In a stationary variable frequency power supply device in which a coolant recirculation pump of a boiling water reactor is driven by the output of a silice inverter, the output station number of the inverter is detected. a frequency detector; a frequency change rate detector that detects the output frequency change rate of the inverter; and when the output of the frequency change rate detector exceeds a predetermined value or the output of the frequency detector and means for stopping the operation of the inverter when a predetermined value is exceeded. (2) Coolant recirculation according to claim 1, wherein the frequency detector detects the output frequency of the inverter from the period of a gate pulse applied to the inverter. Static variable frequency power supply for pump drive. (a) The coolant according to claim 1, wherein the frequency change rate detector detects the output frequency change rate of the inverter from a periodic change in a gate pulse applied to the inverter. A stationary variable frequency power supply device for driving a recirculation pump. (4) The means for stopping the operation of the inverter is configured to stop supplying gate pulses to the inverter. Range 1
A static variable frequency power supply for driving a coolant recirculation pump as described in Section 1. (5) The means for stopping the operation of the inverter includes:
2. A stationary variable frequency positioning device for driving a coolant recirculation pump according to claim 1, wherein said device is adapted to shut off a switch inserted on the input side of said inverter.