# US 11,898,531 B2 · Variable speed pumping systems

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- Number: US 11,898,531 B2
- Document ID: US11898531B2
- Status: Granted
- Kind: B2
- Application number: 17/797,321
- Filed: 2020-02-10
- Published: 2023-02-23
- Granted: 2024-02-13
- Earliest claimed: 2020-02-10
- Assignees: Hitachi Mitsubishi Hydro Corporation
- Applicants: Hitachi Mitsubishi Hydro Corporation
- Inventors: Masahiro Yoshida
- Web page: https://patentgrep.com/patent/US11898531B2

## CPC

- F03B 3/10: characterised by having means for functioning alternatively as pumps or turbines {(starting F03B15/005)}
- F03B 15/06: Regulating, i.e. acting automatically
- F03B 15/00: Controlling (controlling in general G05 {; regulation of plants characterised by the use of siphons F03B13/086})
- H02P 9/007: {Control circuits for doubly fed generators}
- H02P 9/42: to obtain desired frequency without varying speed of the generator
- F05B 2270/1033: Power (if explicitly mentioned)
- F05B 2270/304: Spool rotational speed
- H02P 2101/10: for water-driven turbines
- Y02E 10/20: Hydro energy
- F03B: MACHINES OR ENGINES FOR LIQUIDS (positive-displacement engines for liquid F03C; machines for liquids and gases F01; positive-displacement machines for liquids F04, rotary fluid gearing of the hydrokinetic type F16H41/00)
- H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- F05B: INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A variable speed pumping system includes a generator motor including a frequency converter, in which the variable speed pumping system, in the pumping mode, supply a power command to the generator motor to perform power control, and the power control correction signal generator adds a value obtained by multiplying a signal based on a difference between the power input command and an actual power input measured by a power detector in the pumping mode by a constant gain to a signal based on the deviation and inputs the added value to an integration control element to generate the power control correction signal based on an output signal of the integration control element.

## Claims

### Claim 1

A variable speed pumping system comprising:
a generator motor including a frequency converter and a primary side synchronously connected to a commercial power system although a rotor rotates at a variable speed; and
a pump turbine directly connected to the rotor of the generator motor and configured to drive the generator motor in a power generation mode and to be driven by the generator motor in a pumping mode,
wherein the variable speed pumping system is configured to, in the pumping mode, input to a power controller a value obtained by subtracting an actual power input from a value obtained by adding a power input command to a power control correction signal calculated by a power control correction signal generator based on a deviation between a rotational speed of the rotor and a rotational speed command calculated based on the power input command and supply a power command to the generator motor to perform power control, and
the power control correction signal generator is configured to add a value obtained by multiplying a signal based on a difference between the power input command and an actual power input measured by a power detector in the pumping mode by a constant gain to a signal based on the deviation and input the added value to an integration control element to generate the power control correction signal based on an output signal of the integration control element.