JPH0530686A - Controller for superconducting energy storage device - Google Patents

Abstract

(57) [Summary] [Purpose] To suppress power fluctuations and transient voltage fluctuations by utilizing the characteristics of SMES. [Structure] The active power of a generator 11 near the superconducting energy storage device is used as an input signal 19, and a first output Q _ref (1) is obtained through a bandpass filter 20, a compensation circuit 21 and a control circuit 22. , And the input signal is the voltage of the bus 10 where the superconducting energy storage device is installed 23,
The second Q is passed through the bandpass filter 24 and the control circuit 25.
get _ref (2). Then, in adder 26, Q _ref (1) and Q _ref
(2) is combined and used as the reactive power reference value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a superconducting energy storage device.

[0002]

2. Description of the Related Art Superconducting energy storage device (Supercondu
ctingMagnetic Energy Storage, S for convenience of explanation below
Abbreviated as MES) originally absorbs excess power in the power system and stores it as magnetic energy. When the power becomes insufficient, the magnetic energy is converted into power and the power system is converted. And is controlled so that the demand and supply of electric power in the electric power system are balanced.
However, since SMES has the ability to control the absorption and release of active power and reactive power at high speed by the converter, it is not limited to just energy storage, but a load following function for fast load fluctuations that occur in the power grid, That is, it is expected to contribute to frequency fluctuation control and to system stabilization control such as suppression of power fluctuation and voltage fluctuation. A SMES active power control device has been already proposed (Japanese Patent Application No. 2-59108) for the purpose of load following with respect to fast load fluctuations occurring in the power system.

[0003]

According to the above conventional apparatus, the active power of the SMES is controlled to follow the load in response to a rapid load change, and the reactive power of the SMES is controlled by the static reactive power compensation. Similar to the device (SVC), it maintained only the system voltage constant. The present invention has been made in view of the above circumstances.
An object of the present invention is to provide a control device for a superconducting energy storage device capable of suppressing power fluctuation and transient voltage fluctuation by controlling the reactive power of MES.

[0004]

In order to achieve the above-mentioned object, the present invention uses the active power of a generator near the SMES installation point as an input signal and is obtained through a bandpass filter, a phase compensation circuit and a control circuit. Output and SME
The system voltage near the S installation point is used as an input signal, and the output signal obtained by adding the second output obtained through the bandpass filter and the control circuit is used as the effective signal of SMES.
The reactive power control device has a reactive power reference value. [Operation] If the reactive power of the SMES is controlled so as to match the above-mentioned reactive power reference value, the first output constituting the reactive power reference value acts so as to contribute to suppression of power fluctuation, while , The second output acts so as to contribute to the suppression of transient voltage fluctuations.

[0005]

Embodiments will be described below with reference to the drawings. Figure 1
1 is a configuration diagram of an embodiment for explaining a SMES controller according to the present invention, and FIG. 1 particularly shows a circuit for generating a reactive power reference value in an SMES active / reactive power controller. Note that FIG. 2 cites the entire control block diagram of the SMES active / reactive power control device as a reference. The dotted line portion in FIG. 2 is the content of the already filed application, and is shown for the sake of distinction from the present invention. FIG. 2 will be briefly described. First, the SMES is connected to the busbar via the transformer T. The reactive power Q is detected by the PQ detector from the vicinity of the bus, and it is operated so as to match the command value Q _s (Q _ref during normal operation is zero), α (phase control angle) by the arithmetic circuit, M (control rate) Is calculated and output to each phase GTO. 2 is not the subject of the present invention and will not be described further.

Next, FIG. 1 will be described. In FIG. 1, a bus bar 10 is connected to an SMES (not shown). 11 is SMES
A generator near the installation point, which is connected to a power system 14 via a main transformer 12 and a transmission line 13. 15 is a load transformer,
16 is a load, 17 is a voltage transformer that detects the voltage of the bus 10, 18
Is a current transformer for detecting a current flowing from the generator 11 to the bus 10. Reference numeral 19 is an active power transducer, and the output (DC value) of the active power P _g of the generator 11 is obtained. Reference numeral 20 is a bandpass filter (1) for extracting a component ΔP _g of a certain frequency band in the active power P _g , and 21 and 22 are a phase compensation circuit and a control circuit (1), respectively.

On the other hand, 23 is a voltage transducer, and the voltage V _{s of the} bus bar 10 is obtained at its output (DC value). Reference numeral 24 is a bandpass filter (2) for taking out a component ΔV _s of a certain frequency band in the voltage V _s , and 25 is a control circuit (2). Control circuit (1) 22 output (1) (Q _ref (1)) and control circuit (2)
The outputs (2) (Q _ref (2)) of 25 are combined by the adder 26, and the reactive power reference value (Q _ref ) is obtained as the output.

Next, the operation of the present invention will be described. When the output P _g of the active power transducer 19 is input to the band pass filter 20, a frequency component ΔP _g of a certain band including the power fluctuation frequency (a value around 1 Hz) peculiar to the power system is detected at the output. To be done. In order to suppress the power fluctuation generated in the power system, SMES may be controlled so as to increase the braking torque (power) of the generator, which is a component in phase with the rotation speed ω of the generator. The phase relationship between the phase angle δ of the rotor of the generator and the rotation speed ω is 90 degrees out of phase, so when using ΔP _g (which is in phase with Δδ) as the input signal, the 90 degree phase is compensated and Δω When the voltage rises (falls), the voltage of the bus at the SMES installation point is raised (lowered) to control the reactive power of the SMES so as to increase the active power (→ braking force) of the generator. Therefore, the phase compensating circuit 21 compensates the phase close to 90 degrees as described above, and the control circuit (1) 22 adjusts the extent of the braking effect.

On the other hand, the output V _{s of the} voltage transducer 23
Is input to the bandpass filter 24, the frequency component ΔV _g of a certain band including the power fluctuation frequency peculiar to the power system is detected at the output thereof as in the case of P _g . The control circuit (2) 25 adjusts the degree of the effect of suppressing the voltage fluctuation. Control circuit (1) 22 output (1) (Q _ref (1)
) And the output (2) (Q _ref (2)) of the control circuit (2) 25 are combined by the adder 26 and the reactive power reference value (Q
_ref ) is obtained, but as described above, the action of Q _ref (1) suppresses the power fluctuation, and the action of Q _ref (2) suppresses the transient voltage fluctuation associated with the power fluctuation.

[0010]

As described above, according to the present invention, S
Since the reactive power of the MES is controlled so as to match the reference value, it becomes possible to suppress the power fluctuations occurring in the power system and the transient voltage fluctuations associated with the power fluctuations. The characteristics can be fully utilized.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment for explaining a SMES control apparatus according to the present invention.

FIG. 2 is a reference diagram showing an entire control block of the SMES active / reactive power control device.

[Explanation of symbols]

 10 Bus 11 Generator 17 Voltage transformer 18 Current transformer 19 Active power transducer 20 Bandpass filter (1) 21 Phase compensation circuit 22 Control circuit (1) 23 Voltage transducer 24 Bandpass filter (2) 25 Control circuit (2) 26 adder

Claims (1)

Claim: What is claimed is: 1. A first output is output via a bandpass filter, a phase compensation circuit, and a control circuit using active power of a generator near a superconducting energy storage device as an input signal. At the same time, the second output is obtained via the bandpass filter and the control circuit using the voltage of the bus bar on which the superconducting energy storage device is installed as an input signal,
A control device for a superconducting energy storage device, wherein an output obtained by combining these first and second outputs with an adder is used as a reactive power reference value.